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(Anatomy) Vision: Nature Inspires Design of New Eyes (See)
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adedios
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PostPosted: Sun Nov 20, 2005 12:21 pm    Post subject: (Anatomy) Vision: Nature Inspires Design of New Eyes (See) Reply with quote






Our eyes are among the important sensory systems that we have. With eyes, we are able to see the world around us. Learn more about our visual capability. The news article reminds us that we share this sense with other members of the animal kingdom. Although most animals could see, the degree, quality and sensitivity of vision greatly vary from species to species. The news article provides a brief overview of how scientists are studying vision in various animals in order to create an artificial eye which someday will carry some of the good traits found in the animal kingdom. Explore through the links provided how an eye works. And the following website is a good place to start:

http://faculty.washington.edu/chudler/bigeye.html


Nature Inspires Design of New Eyes
Ker Than
LiveScience Staff Writer
LiveScience.com
Sat Nov 19, 9:00 AM ET

Among all the senses that organisms possess, vision is perhaps the most varied in all the animal kingdom. Millions of years of evolution have produced more than ten different animal vision systems, each perfectly tailored to suit the needs of its owner.

Scientists who look to nature when designing synthetic optics therefore have a lot to choose from. From birds to insects, whales to squid, researchers are taking inspiration from all corners of the animal kingdom when designing artificial eyes.

In today's issue of the journal Science, Luke Lee, a bioengineer from the University of California, Berkeley, reviewed the advances and possibilities.

Two of the most common types of eyes found in nature are the camera-type eye and compound eyes.

Camera-type eyes

The human eye is an example of a camera-type eye, which uses a single lens to focus images onto a light sensitive membrane lining the inside of the eyeball called the retina. Other camera-type eyes exist in nature as well, and some of them are capable of doing neat tricks that our own eyes can''t.


Birds, for example, have special muscles in their eyes that allow them to actively change the thickness of their lens and to alter the shape of their corneas. Whales have special hydraulics in their eyes that let them move their lenses nearer or farther from their retinas. This unique system allows the whales to see well both in and out of water, and to compensate for the increased pressure they experience when they dive.


Though scientists have long known how each component of a camera-type eye works, they are still a long way from being able to create a fully functional artificial eye.

Scientists are making more headway with the other common type of eye found in nature: the compound eye.

Compound eyes

The type found in insects and arthropods, compound eyes are made up of many individual lenses. In dragonflies, for example, a single compound eye can have as many as 10,000.

Some compound eyes process an image in parallel, with each lens sending its own signal to the insect or arthropod's brain. This allows for fast motion detection and image recognition, which is one reason why flies are so hard to swat.

New micromachining technology is allowing researchers to produce tiny artificial compound eyes that mimic those found in insects. Researchers have even managed to arrange the individual lenses around a dome, which may one day be used to crate devices that can see in 360-degrees.

Scientists are now probing nature's vision systems at the molecular level to see if they can figure out how animals get around key engineering problems.

Current infrared sensors, for example, can see more than human eyes can, but they require a sophisticated cooling system to work. Somehow, insects have developed infrared eyes without the need for such a system.

************************************************************

Additional topics to explore:

What is the eye?

http://faculty.washington.edu/chudler/bigeye.html

What is the retina?

http://faculty.washington.edu/chudler/retina.html

How do our eyes see?

http://faculty.washington.edu/chudler/vispath.html

How do you protect your eyes?

http://faculty.washington.edu/chudler/eyesafe.html

What are the common eye disorders?
[Glaucoma][Cataracts][Diabetic Retinopathy][Age-related Macular Degeneration]


http://faculty.washington.edu/chudler/eyed.html

Cataracts
http://www.nlm.nih.gov/medline.....0_no_0.htm

Glaucoma
http://www.nlm.nih.gov/medline.....lesson.htm

Macular Degeneration
http://www.nlm.nih.gov/medline.....lesson.htm

Diabetes and blindness
http://www.nlm.nih.gov/medline.....0_no_0.htm

Why are things colored?

http://webexhibits.org/causesofcolor/0.html

What do animals see?

http://webexhibits.org/causesofcolor/17.html
http://gears.tucson.ars.ag.gov.....ision.html

GAMES

http://www.optima-hyper.com/ey.....IDSAFE.htm
http://www.surfnetkids.com/games/Art_Music_Games/
http://cim.ucdavis.edu/eyes/version1/eyesim.htm
http://www.vision3d.com/


Last edited by adedios on Sat Jan 27, 2007 4:30 pm; edited 4 times in total
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PostPosted: Mon Nov 21, 2005 6:44 am    Post subject: blind spot Reply with quote

Angel,

The blind spot is a fun exercise. Friends and self were discussing it just last week.

http://faculty.washington.edu/.....ision.html

Anyway, keep up the good work.

tony.basa
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PostPosted: Mon Nov 21, 2005 9:43 am    Post subject: Biology 101 Reply with quote

I was browsing looking for some pictures of the ancestor of the modern corn, the teosinte and came across this site.

http://waynesword.palomar.edu/bio100.htm

It seems interesting. I have just finished reading Jared Diamond's Pulitzer-winning book "Guns, Germs, and Steel". It's very engrossing. An easy read that I recommend to everybody.

cheers!
tony.basa
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PostPosted: Mon Nov 21, 2005 1:12 pm    Post subject: Reply with quote

Tony;

Thanks for taking time to look at the articles and links that I have posted. I just hope that the teachers and students in Paete will do the same.
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PostPosted: Mon Jan 09, 2006 11:20 am    Post subject: Newfound Eye Cells Sense Night and Day Reply with quote

Newfound Eye Cells Sense Night and Day
By Sara Goudarzi
Special to LiveScience
posted: 09 January 2006
07:36 am ET

Sometimes a discovery is right in front of your eyes. Scientists found a new class of cells in the eye that are sensitive to light responsible for regulating the body's circadian clock.

The eye's retina contains light receptors known as cones and rods. These receptors receive light, convert it to chemical energy, and activate the nerves that send messages to the brain. They were thought to be the only photoreceptors in the retina of the eye.

"When we began to do our work, we knew there might have been a missing photoreceptor,” said David Berson, professor of neuroscience at Brown University.

"We asked ourselves if there is a third class, and the answer turned out to be yes.”

The discovery was made with mice, whose eyes are thought to function similarly to humans. It was recently published in the journal Neuron.

Three-year effort

Berson's suspicion about the unknown photoreceptor class came from the knowledge that blind mice still adjusted their circadian clocks to day and night. Three years ago, Berson and his team discovered a complimentary system in the eye with photosensitive retinal cells. The full capability of the cells was not apparent, however.

These cells, numbering about 2,000 in the eye, send electrical messages to the brain, which constricts the pupil and gives the brain information about circadian rhythms.

They are called intrinsically photosensitive retinal ganglion cells, or ipRGCs.

"Until now, we didn't know if these cells were adaptive to lighting conditions,” said Kwoon Wong, a postdoctoral research fellow in the Berson lab and the lead author of the Neuron paper. "Now we know that they are. Compared with rods and cones, they're glacially slow and they don't adjust their sensitivity as completely.”

Whereas rods and cones rapidly communicate changes in brightness and are responsible for coloring our world, the new class of cells send signals about overall brightness, somewhat like the light meter of a camera, telling the brain when it is night and when it is day.

"What's peculiar about these cells is that [unlike the rods and the cones] they are output cells, meaning they communicate directly with the brain,” Berson explained. "Rods and cones on the other hand communicate only with other retinal cells and have to go through two or three levels before they communicate with the brain.”

Better understanding

This new understanding of how the eye works may be helpful in those who are blind and have degenerated rods and cones.

"Certain people who are blind and have no conscious perception of light may still have components of a functioning visual system,” Berson told LiveScience. "This new recognition suggests being careful about procedures such as removing an eye [when deemed ineffective].”

The work also helps in understanding how biological clocks work with the rising and setting of the sun and the mechanisms involved in recovery from jetlag.

Berson and his colleagues are now hot on the question of how these cells work.

"We have this well in hand for rod and cone photoreceptors; now we have to do it all over again for this new class of photoreceptors,” Berson said. "We also need to find out how these cells interact with one another.”

Source
http://livescience.com/humanbi.....cells.html

How the eye works

http://www.livescience.com/hum.....works.html
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PostPosted: Sat Feb 04, 2006 10:07 am    Post subject: Window to the Heart: New Eye Exam Spots Disease Risk Reply with quote

Window to the Heart: New Eye Exam Spots Disease Risk
By Robin Lloyd
Special to LiveScience
posted: 03 February 2006
09:27 am ET



Some say the eyes are the window to the soul, but an Australian medical researcher says they are the window to the heart and beyond.

Tien Wong of the Center for Eye Research Australia at the University of Melbourne has shown in several large-scale studies that abnormalities of the blood vessels in the retina can be used to predict patients' risk for diabetes, hypertension (or high blood pressure), stroke and heart disease.

These four disorders are some of the most common causes of death, hospitalization and disability in the developed world. But the ability to predict them is limited.

In plain sight


Wong's approach involves analyzing digital photographs of patients' retinas and studying them to find narrowing or ballooning of the small blood vessels. Systemic diseases—those that affect several organs or the whole body—such as hypertension, diabetes, AIDS, Graves' disease, lupus, atherosclerosis, multiple sclerosis, rheumatoid arthritis, and sickle cell anemia often cause changes in the eye that can show up as red dots or small blood clots.

Blood vessels of the eyes are so predictive because they are part of the brain's vascular system, so they share anatomical features and respond similarly to stress and disease, Wong said.

In fact, eyes are so transparent compared to the rest of the body that they are the only organ that allows physicians to directly see blood vessels. The digital photography approach is non-invasive—no blood is taken, no incisions are made, no probes in orifices. It takes just a few seconds.

Wong has shown that retinal abnormalities are a good predictor of whether a patient will develop high blood pressure or die of cardiac disease in the next 10 years.

"My hope is that one day, retinal imaging will be able to provide an additional means to stratify risk and help identify people who may benefit from early lifestyle changes and preventive therapies,” Wong told LiveScience.

Eyes on the Internet

The idea that the eye is a window to the human body has been around for more than a century, but Wong has figured out how to make precise and quantifiable predictions for illness based on retinal abnormalities that can be used as a standard by all doctors.

Wong sees a future in which physicians include retinal data in making treatment decisions. First, they'll need to arrive at a common classification system for diagnosing retinal abnormalities.

Ultimately, Wong and his colleagues, who now are setting up a Retinal Vascular Imaging Center in Melbourne, plan to develop a Web-based system to which doctors can upload digital images of patients' retinas. The system will report back the extent of a patient's cardiovascular disease.

It remains to be seen, though, how useful the system will be and with how many diseases it may prove helpful.

Emily Chew, a medical researcher at the National Eye Institute in Bethesda, said she was not surprised by Wong's findings relating retinopathy with diabetes.

"It is important for all persons with diabetes to have regular eye exams (annually) and for those over 65 to have eye exams on a yearly basis to detect any eye disease that maybe treatable, Chew said in an email interview.

However, Chew said eye exams will pick up only a small percentage of the population that have other systemic diseases and "one would not screen with eye exams for systemic diseases.”
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PostPosted: Sun May 21, 2006 9:18 am    Post subject: Eyeballs vs Footballs: The Final Reply with quote

Heidelberg, 19 May 2006
Springer-Verlag

Eyeballs vs Footballs: The Final
http://www.springer-sbm.com/in....._news=2508
Limitations of human visual system hinders goalkeepers from predicting free kicks

Professional goalkeepers fail to stop free kicks because of shortcomings in their visual system, according to new research by Cathy Craig and colleagues, from Queen’s University Belfast, Northern Ireland. The projected trajectory of a ball following a curved flight path is more difficult to judge because our visual system is not sensitive enough to gauge a change of direction at speed, mid-flight. The research is published in Springer-Verlag’s journal Naturwissenschaften.

Free kicks are now important goal-scoring opportunities, with specialist free kick takers often choosing to make the ball spin in order to curve the ball into the goal. Because of the size of the goalmouth, goal keepers need to anticipate the direction of the ball before they take action. Cathy Craig and team looked at whether the lateral deflection of a ball’s trajectory, caused by sidespin2, affects professional footballers’ perception of where the ball is heading.

Eleven professional footballers (attackers, mid-fielders and defenders) and nine goalkeepers from AC Milan, Olympique de Marseille, Bayer Leverkusen and Schalke 04 were asked to judge whether a range of simulated free kicks would end up in the goal or not, using a virtual reality system. The viewpoint was fixed in the centre of the goal. When there was no spin, balls arriving directly opposite the goal were consistently judged to be entering the goal. When the ball was spinning clockwise, the resulting trajectories – from the point of view of the goalkeeper – unfolded on the right-hand side of the no-spin trajectory, resulting in a goal only if the striker shot from left of the central position in front of the goal. For conditions where the ball was spinning counter-clockwise, the balls landed in the goal only when they – from the view of the striker – were kicked from the right-hand side of the no-spin trajectory. There was no difference between the judgements of the field players and goalkeepers.

Players appear to be using current ball heading direction to make their judgements about whether the free kick will end up in the goal or not, rather than accurately predicting the effects of lateral acceleration on the ball’s trajectory. Craig and colleagues conclude that these “perceptual effects find their origin in inherent limitations of the human visual system in anticipating the arrival point of an object subjected to an additional accelerative influence….The depth of experience of our participants does not seem to be able to compensate for these shortcomings in visual perception.”

1. Craig CM et al (2006). Judging where a ball will go: the case of curved free kicks in football. Naturwissenschaften; 93:97-101.


2. The Magnus force, created by a ball spinning around an axis, gives rise to an acceleration that is perpendicular to the direction of the ball. This causes a lateral deviation
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PostPosted: Wed May 24, 2006 7:52 am    Post subject: MIT poet develops 'seeing machine' Reply with quote

MIT poet develops 'seeing machine'
Elizabeth A. Thomson, News Office
MIT
May 23, 2006


An MIT poet has developed a small, relatively inexpensive "seeing machine" that can allow people who are blind, or visually challenged like her, to access the Internet, view the face of a friend, "previsit" unfamiliar buildings and more.

Recently the machine received positive feedback from 10 visually challenged people with a range of causes for their vision loss who tested it in a pilot clinical trial. The work was reported in Optometry, the Journal of the American Optometric Association, earlier this year.

The work is led by Elizabeth Goldring, a senior fellow at MIT's Center for Advanced Visual Studies. She developed the machine over the last 10 years, in collaboration with more than 30 MIT students and some of her personal eye doctors. The new device costs about $4,000, low compared to the $100,000 price tag of its inspiration, a machine Goldring discovered through her eye doctor.

Goldring's adventures at the intersection of art and high technology began with a visit to her doctor, Lloyd Aiello, head of the Beetham Eye Institute of the Joslin Diabetes Center. At the time, Goldring was blind. (Surgeries have since restored vision in one eye).

To better examine her eyes, Aiello asked her to go to the Schepens Eye Research Institute at Harvard, where technicians peered into her eyes with a diagnostic device known as a scanning laser opthalmoscope, or SLO. With the machine they projected a simple image directly onto the retina of one eye, past the hemorrhages within the eye that contributed to her blindness. The idea was to determine whether she had any healthy retina left.

It turns out that she did, and was able to see the image -- a stick figure of a turtle. But the turtle wasn't very interesting, Goldring said. So she asked if they could write the word "sun" and transmit that through the SLO. "And I could see it!" she said. "That was the first time in several months that I'd seen a word, and for a poet that's an incredible feeling."

She went on to use the device for many other visual experiences. For example, she developed a "visual language" consisting of short words that incorporate graphics and symbols that convey the meaning of words and make them easier to see and read.

But although the SLO held promise as more than a diagnostic device, it had serious drawbacks. In addition to the prohibitive cost, the SLO is large and bulky. Goldring determined to develop a more practical machine for the broader blind public.

She did so by collaborating over the past several years with Rob Webb, the machine's inventor and a senior scientist at the Schepens Eye Research Institute; Aiello; Dr. Jerry Cavallerano, an optometrist at Joslin; William Mitchell, former dean of MIT's School of Architecture and Planning and now a professor in the Program in Media Arts and Sciences; the late Steve Benton, an acclaimed optical physicist and MIT professor; and former MIT affiliate James Cain.

She has also worked with dozens of MIT graduate students and undergraduates, including Sylvia Gonzalez (S.B. 2003) and Shima Rayej (S.B. 2004), who helped design and construct the seeing machine.

"We essentially made the new machine from scratch," Goldring said. While still allowing the projection of images, video and more onto a person's retina, the new desktop device costs much less than its predecessor in part because it doesn't include the diagnostic feedback of the SLO. The new seeing machine also replaces the laser of the SLO with light-emitting diodes, another source of high-intensity light that is much cheaper. Like its inspiration, the seeing machine is designed to be used by one eye.

The pilot clinical trial of the seeing machine involved visually impaired people recruited from the Beetham Eye Institute. All participants had a visual acuity of 20/70 or less in the better-seeing eye. A person with 20/70 vision can see nothing smaller than the third line from the top of most eye charts. Most participants, however, had vision that was considered legally blind, meaning they could see nothing smaller than the "big E" on a standard eye chart.

With her weak eye, Goldring can distinguish between light and dark and she can see hand movement, although not individual fingers. She cannot recognize faces or read.

Subjects "had a wide range of cause for vision loss, including diabetic retinopathy, macular degeneration (the fastest growing cause of blindness), and visual field loss," said Cavallerano, a coauthor of the paper and another of Goldring's doctors.

Participants used the machine to view 10 examples of Goldring's visual language. A majority -- six -- interpreted all 10 "word-images" correctly. "They responded really well to the visual language," Goldring said. "One woman told me she would love to see recipes written that way."

They also used the machine to navigate through a virtual environment, raising the potential for "previewing" unfamiliar buildings a person wants to visit.

Goldring explained that visually challenged people are often terrified of going to new places. "There's a fear of missing simple visual cues, steps and not being able to decipher elevator buttons." (She noted that less than 10 percent of the blind read Braille.) Further, bystanders who aim to help -- "there are five steps there; it's the third door on the left" -- are often wrong, especially people with good vision, Goldring said. "If you are visually challenged, if you see something once using the machine, you remember."

Participants explored the virtual environment -- which represented the inside of an MIT building -- via a joystick that allowed them to move forward, backward and sideways.

All of the participants reported that the machine "may have the potential to assist their mobility in unfamiliar environments," according to the Optometry article. Concluded Goldring: "A couple of them said they'd tried every seeing aid available (magnifying devices, etc.), and this was by far the best, even in this rough, rough shape."

Goldring and colleagues are now working toward a large-scale clinical trial of a color seeing machine (the device tested in the pilot trial was black and white). With the color version, participants can explore a museum gallery containing some of Goldring's art. When a person gets close enough to a piece, the work is explained in Goldring's voice.

This work was supported by NASA and by MIT's School of Architecture and Planning, Center for Advanced Visual Studies, Undergraduate Research Opportunities Program and Council for the Arts.
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PostPosted: Mon Jul 17, 2006 7:05 pm    Post subject: Scientists discover why cornea is transparent Reply with quote

Public release date: 17-Jul-2006
Schepens Eye Research Institute

Scientists discover why cornea is transparent and free of blood vessels, allowing vision

Results hold promise for treatments of eye disease and cancer
Boston, MA -- Scientists at the Harvard Department of Ophthalmology's Schepens Eye Research Institute and Massachusetts Eye and Ear Infirmary (MEEI) are the first to learn why the cornea, the clear window of the eye, is free of blood vessels--a unique phenomenon that makes vision possible. The key, say the researchers, is the unexpected presence of large amounts of the protein VEGFR-3 (vascular endothelial growth factor receptor-3) on the top epithelial layer of normal healthy corneas. According to their findings, VEGFR-3 halts angiogenesis (blood vessel growth) by acting as a "sink" to bind or neutralize the growth factors sent by the body to stimulate the growth of blood vessels. The cornea has long been known to have the remarkable and unusual property of not having blood vessels, but the exact reasons for this had remained unknown.

These results, published in the July 25, 2006 issue of the Proceedings of the National Academy of Sciences and in the July 17 online edition, not only solve a profound scientific mystery, but also hold great promise for preventing and curing blinding eye disease and illnesses such as cancer, in which blood vessels grow abnormally and uncontrollably, since this phenomenon, present in the cornea normally, can be used therapeutically in other tissues.

"This is a very significant discovery," says Dr. Reza Dana, Senior Scientist at the Schepens Eye Research Institute, head of the Cornea Service at the Massachusetts Eye and Ear Infirmary, and an associate professor at Harvard Medical School, and the senior author and principal investigator of the study. "A clear cornea is essential for vision. Without the ability to maintain a blood-vessel-free cornea, our vision would be significantly impaired," he says, adding that clear, vessel-free corneas are vital to any animal that needs a high level of visual acuity to survive.

The cornea, one of only a few tissues in the body that actively keep themselves vessel-free (the other is cartilage), is the thin transparent tissue that covers the front of the eye. It is the clarity of the cornea that allows light to pass onto the retina and from there to the brain for interpretation. When the cornea is clouded by injury, infection or abnormal blood vessel growth, vision is severely impaired, if not destroyed.

Scientists have been wrestling with the "clarity" puzzle for many decades. And, while some previous studies have revealed small clues, none have pointed to one major mechanism, until this study.

In most other tissues of the body, blood vessel growth or angiogenesis occurs in response to a need for increased blood flow to heal an injured or infected area. The immune system sends in growth factors such as vascular endothelial growth factor (VEGF) to bind with a protein receptor called VEGFR-2 on blood vessels to trigger vessel growth. Three forms of VEGF--A, C, and D--bind with this receptor. Two of them, C and D also bind with VEGFR-3, which is usually found on cells lining lymphatic vessels, to stimulate the growth of lymphatic vessels.

Dana's team began to suspect the involvement of VEGFR-3 in stopping blood growth in corneas when they noticed unexpectedly that large amounts of the protein seemed to exist naturally on healthy corneal epithelium, a previously unknown location for the receptor. Dana and his team were already aware from clinical experience that the epithelium most likely played a role in suppressing blood vessel growth on the cornea, having witnessed blood vessels develop on corneas stripped of their epithelial layers.

They began to theorize that the large amounts of VEGFR-3, in this new, non-vascular location, might be attracting and sucking up all the C and D VEGF growth factors, thereby blocking them from binding with VEGFR-2. And, because this binding took place in a non-vascular setting, the growth factors were neutralized.

To test their theory, the team conducted a series of experiments.

Using corneal tissue from mice, the team did the following.

They conducted chemical analyses that demonstrated that VEFGR-3 and the gene that expressed it were indeed present on the corneal epithelium. Next, in two separate experiments, they compared corneas with and without epithelial layers that were injured. They found that only the corneas without epithelial layers developed blood vessels, implicating the role of the epithelium in suppressing blood vessel growth To further prove their theory, they added a VEGFR-3 substitute to corneas stripped of their epithelial layers and found that vessel growth continued to be suppressed, replacing the normal anti-angiogenic role of the epithelium. Finally they exposed intact corneas to an agent that blocked VEGFR-3 and found that blood vessels began to grow, formally demonstrating that the corneal epithelium is key to suppression of blood vessels and that the key mechanism is expression of VEGFR-3.

"The results from this series of tests, confirmed our belief that the presence of VEGFR-3 is the major factor in preventing blood vessel formation in the cornea," says Dana, who says that the discovery will have a far reaching impact on the development of new therapies for eye and other diseases.

"Drugs designed to manipulate the levels of this protein could heal corneas that have undergone severe trauma or help shrink tumors fed by rapidly growing abnormal blood vessels," he says. "In fact, the next step in our work is exactly this."


###
Other authors of the study include: Claus Cursiefen* +, Lu Chen*, Magali Saint-Geniez*, Pedram Hamrah*, Yiping Jin*, Saadia Rashid*, Bronislaw Pytowski**, Kris Persaud**, Yan Wu**, J. Wayne Streilein*†, Reza Dana* ++ ,

*The Schepens Eye Research Institute and Massachusetts Eye and Ear Infirmary, Dept. of Ophthalmology, Harvard Medical School, Boston, MA; +Dept. of Ophthalmology, Friedrich-Alexander University Erlangen-Nürnberg, Erlangen, Germany; **ImClone Systems, Inc., New York; †Dr. J. Wayne Streilein deceased March 15 th 2004.

About the Massachusetts Eye and Ear Infirmary,
http://www.meei.harvard.edu.: The Massachusetts Eye and Ear Infirmary, an independent specialty hospital, is an international center for treatment and research and a teaching hospital of Harvard Medical School.

Schepens Eye Research Institute is an affiliate of Harvard Medical School and he largest independent eye research institute in the world. For additional information, go to http://www.theschepens.org/.
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PostPosted: Fri Aug 11, 2006 7:36 am    Post subject: Night Vision: How Snakes Get Clear Picture of Prey Reply with quote

Night Vision: How Snakes Get Clear Picture of Prey

By Jeanna Bryner
Special to LiveScience
posted: 10 August 2006
09:52 am ET



Without a trip to an eye doctor, some snakes have developed their own vision-correcting devices. Scientists have discovered how pit vipers can turn blurry blobs into useful images with striking clarity.

Turns out it's all in their tiny minds.

Two groups of snakes, pit vipers and boids (a family that includes boa constrictors) sport a pit organ on either side of their heads. Stretched across each pencil-eraser-size cavity is a membrane that can detect infrared light—which is heat—emitted by nearby prey. Scientists have known that pit vipers utilize these organs similar to the way a pinhole camera works.

For the full article:

http://www.livescience.com/ani....._eyes.html
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PostPosted: Fri Oct 27, 2006 6:37 pm    Post subject: Eyelids Alter Shape of the Eye Reply with quote

Eyelids Alter Shape of the Eye

By Robin Lloyd
Special to LiveScience
posted: 27 October 2006
02:36 pm ET

The pressure of the eyelid on the eyeball could cause one of the most common vision problems, new research shows.

The work builds on previous research showing that heavy reading can change the shape of the eye during the day, temporarily degrading eyesight.

Imperfections in the shape of the cornea, a transparent shield that protects and covers the front of the eyeball, often causes corneal astigmatism. The condition, which affects somewhere between 33 and 60 percent of all people, can lead to distorted vision.

The study of 100 normal-sighted young subjects showed that the shape of the eyelid opening at different angles of gaze affected the shape of the cornea, says Scott Read of Queensland University of Technology, in Brisbane, Australia.

For the full article:

http://www.livescience.com/hum.....ision.html
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PostPosted: Tue Nov 07, 2006 3:46 pm    Post subject: Why Eyes are So Alluring Reply with quote

Why Eyes are So Alluring

By Ker Than
LiveScience Staff Writer
posted: 07 November 2006
09:00 am ET



For humans, the eyes are more than just windows to the outside world. They are also portals inward, providing others with glimpses into our inner thoughts and feelings.

Of all primates, human eyes are the most conspicuous; our eyes see, but they are also meant to be seen. Our colored irises float against backdrops of white and encircle black pupils. This color contrast is not found in the eyes of most apes.

According to one idea, called the cooperative eye hypothesis, the distinctive features that help highlight our eyes evolved partly to help us follow each others' gazes when communicating or when cooperating with one another on tasks requiring close contact.

For the full article:

http://www.livescience.com/hum....._eyes.html
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PostPosted: Mon Dec 18, 2006 11:07 am    Post subject: Picture Perfect: How to Make Blink-Free Holiday Photos Reply with quote

Picture Perfect: How to Make Blink-Free Holiday Photos

By Corey Binns
Special to LiveScience
posted: 18 December 2006
09:22 am ET

The group holiday photo shoot is anything but a snap, especially if you want to catch everyone with their eyes open.

To help photographers get the perfect shot, an Australian scientist has calculated the number of photos that need to be taken to ensure at least one blink-free photo.

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http://www.livescience.com/oth.....rfect.html
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PostPosted: Fri Jan 05, 2007 9:09 am    Post subject: New study challenges 'critical period' in childhood vision d Reply with quote

Association for Psychological Science
4 January 2007

New study challenges 'critical period' in childhood vision development

Understanding how the human brain learns to perceive objects is one of the ultimate challenges in neuroscience. In 2003, Pawan Sinha, a professor at the Massachusetts Institute of Technology, launched an initiative with the hopes of shedding some light on the acquisition of visual skills. The goal of his "Project Prakash" is to find, treat, and study congenitally blind children in India. A unique case study that resulted from this project appears in the December 2006 issue of Psychological Science.

Dr. Sinha and two graduate students, Yuri Ostrovsky and Aaron Andalman, were introduced to a woman in India who was born blind due to dense congenital cataracts in both eyes. The woman lived as a blind child for 12 years before she received treatment. Now, twenty years after her surgery, the researchers found that she is able to discern between separate objects, determine depth, localize faces amongst a background of natural scenes, and match faces by their identity. This case demonstrated that a person can acquire visual function even after being deprived of sight for an extended period during childhood.

The evidence gathered from this case study presents a scientific alternative to the widely noted "critical period" that the brain undergoes during childhood. The critical period theory asserts that the brain's learning mechanisms are significantly dependent on early sensory stimulation. Sinha and his colleagues posit that while some aspects of vision, such as acuity, might indeed be subject to critical periods, many other aspects of functional vision might be learnable even at later ages. In other words, perhaps our brain is not as rigid as we think, and its plasticity remains even after several years of compromised sensory experience. The results of this study provide an argument for even late-stage blindness treatments and guide researchers towards an improved understanding of the complexities of the brain.
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PostPosted: Fri Jan 19, 2007 1:05 pm    Post subject: TEARS REVEAL SOME OF THEIR DEEPEST SECRETS TO RESEARCHERS Reply with quote

TEARS REVEAL SOME OF THEIR DEEPEST SECRETS TO RESEARCHERS

Ohio State University
19 January 2007

COLUMBUS , Ohio – It's no secret why we shed tears. But exactly what our tears are made of has remained a mystery to scientists.

A new study sheds some light on the complex design of tears. What we think of as tears, scientists call tear film, which is made up of three distinct, microscopic layers. The middle, watery layer – what we normally think of as tears when we cry – is sandwiched between a layer of mucus and an outer layer of fatty, oily substances collectively called meibum.

It's in this outer layer that researchers describe, for the first time, a new class of lipids – a type of fat – that make up part of the film. They also identified one of these lipids, oleamide, which had not been known to be a part of tears before.

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http://researchnews.osu.edu/archive/eyefat.htm
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PostPosted: Sat Mar 03, 2007 8:04 am    Post subject: Look into My Eyes Reply with quote

Look into My Eyes
Emily Sohn

March 7, 2007

If you look deep into a friend's eyes, you may imagine that you can see his or her thoughts and dreams.
But more likely, you'll simply see an image of yourself—and whatever lies behind you.

Our eyeballs are like small, round mirrors. Covered by a layer of salty fluid (tears), their surfaces reflect light like water reflects from a pond.

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http://www.sciencenewsforkids......ature1.asp
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PostPosted: Fri Mar 16, 2007 7:30 am    Post subject: Study: Playing Video Games Improves Eyesight Reply with quote

Study: Playing Video Games Improves Eyesight

By LiveScience Staff

posted: 15 March 2007
05:03 pm ET

Playing "Gears of War," "Lost Planet," "Halo" and other action video games that involve firing guns can improve your eyesight, new research claims.

Sedate games like "Tetris" don't work.

People who started out as non-gamers and then received 30 hours of training on first-person action video games showed a substantial increase in their ability to see objects accurately in a cluttered space, compared to non-gamers given the same test, said Daphne Bevelier of the University of Rochester.

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http://www.livescience.com/hum.....ision.html
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PostPosted: Fri Mar 23, 2007 2:24 pm    Post subject: Genetically Tweaked Mice Get Human-Like Vision Reply with quote

Genetically Tweaked Mice Get Human-Like Vision

By Ker Than
LiveScience Staff Writer
posted: 22 March 2007
05:16 pm ET

Scientists have some lab mice seeing red. The animals had their vision genetically upgraded and can now see colors normally invisible to rodents.

The finding, detailed in the March 23 issue of the journal Science, has implications for the evolution of full-color, or “trichromatic,” vision in our own ancestors.

“What we are now looking at in these mice is the same evolutionary event that happened in one of the distant ancestors of all primates,” said study team member Jeremy Nathans of Johns Hopkins University.

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http://www.livescience.com/ani....._mice.html
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PostPosted: Mon Apr 02, 2007 8:23 am    Post subject: Jellyfish Have Human-Like Eyes Reply with quote

Jellyfish Have Human-Like Eyes

By Andrea Thompson
LiveScience Staff Writer
posted: 01 April 2007
02:53 pm ET

A set of special eyes, similar to our own, keeps venomous box jellyfish from bumping into obstacles as they swim across the ocean floor, a new study finds.

Unlike normal jellyfish, which drift in the ocean current, box jellyfish are active swimmers that can rapidly make 180-degree turns and deftly dart between objects. Scientists suspect that box jellyfish are such agile because one set of their 24 eyes detects objects that get in their way.

“Behavior-wise, they’re very different from normal jellyfish,” said study leader Anders Garm of Lund University in Sweden.

The eyes of box jellyfish are located on cup-like structures that hang from their cube-shaped bodies.

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http://www.livescience.com/ani....._eyes.html
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PostPosted: Sat May 12, 2007 6:50 am    Post subject: The Blurry World of Claude Monet Recreated Reply with quote

The Blurry World of Claude Monet Recreated
By Andrea Thompson, LiveScience Staff Writer

posted: 11 May 2007 02:18 pm ET

Claude Monet's paintings diffuse into nothing more than a fuzzy riot of color when viewed too closely. Ironically, the impressionist's vision got cloudy late in life, and his whole world blurred like, well, like a Monet. Now scientists have recreated the world as Monet saw it.

The new perspective reveals how the painter's failing vision might have affected his work.

Using historical accounts, Stanford ophthalmologist Michael Marmor estimated the artist's level of impaired vision and with a computer, applied blur and color variation to match the different stages of his declining eyesight, transforming the varied colors of the Monet's "Japanese Bridge" into dark and muddy shades of yellow-green.

Marmor also performed the same analysis on works by Edgar Degas, who suffered from an eye disease that warped his central vision.

"What is new in this work is to actually show what that meant to them, and I don't think it's been appreciated ever in the past, really how this visual loss affected their perception of their own work," Marmor said.

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http://www.livescience.com/his.....sease.html
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PostPosted: Wed Jun 13, 2007 8:44 pm    Post subject: Genetic research and retinal diseases Reply with quote

Genetic research and retinal diseases

STAR SCIENCE By Yasmyne S. Castillo-Ronquillo, MD, DPBO and Joseph Ranche, MD, DPBO

http://philstar.com/index.php?.....2007061376

Thursday, June 14, 2007

The retina is that part of the eye on which light energy is converted into signals that are relayed to the visual centers in the brain. If you think of the eye as a camera, the retina is the film. Retinal degenerative disease is diagnosed mainly in the adult population. Some patients have incapacitatingly poor vision before they turn 40 while others live to their 70s with minimal visual problems. Retinitis pigmentosa, one of the degenerative retinal diseases, is caused by the destruction of the rods. The rods are the retinal cells that act as photoreceptors in light and dark adaptation. The cones, retinal photoreceptors that subserve color vision, are preserved. Retinitis pigmentosa has been discovered to have a genetic basis.

Genetics is the science that helps us understand how the biological nature of parents influences that of their children through the transmission of genes. Genes themselves are stretches of the long, chain-like molecules of DNA (deoxyribonucleic acid) that are embedded in the microscopic structures known as chromosomes within living cells. Each gene serves as a repository of information enabling a cell to produce one or more kinds of proteins that themselves perform specific biological tasks. A change in the chemical structure of a gene constitutes a mutation, which can alter the quantity or quality of proteins produced by cells and thereby result in disease. For example, retinitis pigmentosa is known to be caused by certain mutations in the genes for the proteins rhodopsin and arrestin — both of which play key roles in the light-sensing process in rods. What techniques are used to discover the mutations in these genes?

Linkage analysis is one technique that is used in the genetic studies of retinitis pigmentosa. Linkage is the tendency for genes and genetic markers to be inherited together because of their location near one another on the same chromosome. A genetic marker is simply a segment of DNA whose physical location on a chromosome is known and whose inheritance can be followed from one generation to the next. Markers are often used as tools for tracking the inheritance pattern of a gene that has not yet been identified.

To study the genes involved in retinitis pigmentosa, DNA is needed from both affected and unaffected members of a family suspected to have a hereditary form of the disease. This DNA is subjected to a chemical process known as PCR (Polymerase Chain Reaction), which selectively replicates specific portions of the DNA to yield collections of DNA fragments of varying lengths. These DNA fragments are then separated according to size in a gel with the aid of electrical force, producing distinctive patterns (analogous to the lines of a barcode) that are subsequently studied by linkage analysis.

Linkage analysis is used for gene hunting and genetic testing through the use of LOD scores (Log of Odds ratio). The LOD score is used to decide whether an observed pattern of inheritance in a family arose by chance alone or as a consequence of genetic linkage. The LOD score is a statistical measure of the likelihood that two positions on a chromosome are near enough to each other so as to be consistently inherited together, in which case they are said to be linked. A Lod Score of 3 or higher strongly suggests that the suspected mutant gene and the known genetic marker being followed are in fact linked. A chromosomal region likely to contain the gene of interest can be defined around the position of a known genetic marker to which it is linked, and candidate genes can then be selected from the set of genes identified within the region as determined from the DNA sequence data of the Human Genome Project (HGP). (Completed in 2002 by the US National Institutes of Health, the HGP involved the participation of hundreds of scientists in many laboratories worldwide.)

Identifying the exact gene among the candidate genes requires many more steps. Once this gene is identified, gene mutation studies are performed. This consists of analyzing the DNA sequence of the mutant gene and determining its difference from the normal gene. With the use of linkage analysis and mutation screening techniques, discovery time for gene-disease association and gene-mutation identification is shortened.

Mutation screening refers to the identification of mutations that have altered the quantity or quality of proteins produced by cells, or have otherwise resulted in some form of biological change. The complete DNA sequence of a mutated gene may be determined for this purpose, but even just a part of this DNA sequence may suffice to disclose mutations. In the latter case, PCR can be used to produce a relatively short segment of the gene within which mutations are known to occur frequently; this strategy often leads to the identification of mutations without having to study the entire DNA sequence, thus saving on time and other resources.

We have reviewed the records of 44 patients with retinitis pigmentosa at the Sentro Oftalmologico Jose Rizal, Philippine General Hospital, University of the Philippines Manila. The patients ranged from eight to 72 years old. They complained of chronic, progressive clouding of vision and night blindness. Eighty percent of them were documented to have retinal changes and visual impairment as defined by World Health Organization (WHO) standards. The genetic changes, if any, that have caused retinitis pigmentosa in these patients are puzzles that remain to be solved.

Several eye research centers in the United States, Europe and Asia are participating in an effort to find novel genes and gene mutations that cause retinitis pigmentosa. The ultimate goal of genetic retinal research is definitive treatment or at the very least, a better management of retinal diseases so that our patients will maintain good visual function as long as possible.

* * *

Joseph Ranche, MD, is presently a research fellow in Ocular Pathology at the Institute of Ophthalmology, National Institutes of Health, UP Manila. He recently graduated from the ophthalmology residency program of UPPGH.

Yasmyne S. Castillo-Ronquillo, MD, DPBO (Diplomate of the Philippine Board of Ophthalmology), is an associate professor of Biochemistry and Molecular Biology of the UP College of Medicine; chief of Ocular Pathology of the Institute of Ophthalmology, UP National Institutes of Health, and a consultant of the Department of Ophthalmology and Visual Sciences, UPPGH.
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PostPosted: Tue Jul 03, 2007 9:25 am    Post subject: Understanding Smooth Eye Pursuit - The Incredible Targeting Reply with quote

Understanding Smooth Eye Pursuit - The Incredible Targeting System of Human Vision
University of Pennsylvania

June 26, 2007


PHILADELPHIA -- Researchers at the University of Pennsylvania have shed new light on how the brain and eye team up to spot an object in motion and follow it, a classic question of human motor control. The study shows that two distinctly different ways of seeing motion are used - one to catch up to a moving object with our eyes, a second to lock on and examine it.

"Without the ability to lock our eyes onto a moving target, something called smooth pursuit, athletes cannot 'keep their eye on the ball,' and a person walking down the street cannot examine the facial expression or identity of a passerby," said Jeremy Wilmer, postdoctoral fellow in the Department of Psychology in Penn's School of Arts and Sciences and lead author of the study.

Researchers found that volunteers showed a range of capabilities when it came to sensing and following motion, and the careful measurement of such differences produced novel insights into the workings of the smooth pursuit system.

"Our automatic tendency is to assume you and I see the same baseball, or color, or face, but in fact our experiences can be quite different," Wilmer said. "The assumption of a common visual experience can backfire when we assume wrongly that the person next to us perceives the same flying projectile, or red hexagonal sign, or emotion that we do."

Researchers explored the two ways of perceiving motion to see how each contributes to smooth pursuit. The first, called low-level motion perception, is the sense one gets of disembodied motion before knowing what is moving. The second, called high-level motion perception, is the ability to watch an object move through time and space after it has been recognized.

Participants who were good at low-level motion perception caught up to a moving object with their eyes more easily. A completely different set of volunteers exhibited skill at high-level motion perception and were much better at locking onto a moving target once their eyes caught up to it. This result shows that distinct experiences of motion drive different stages of smooth pursuit.

"Our experience of the world normally appears quite seamless," Wilmer said, "but in fact our brain sees many aspects separately and knits them together into one experience of the world."

The study result builds on research into how piecemeal processing in the brain leads to holistic experience and seamless behavior. It also provides insight into a smooth pursuit system important for both social skills and sports. The first in-depth study of how individuals differ from each other in their ability to sense and follow motion, this research sets the stage for future studies of genetic and environmental influences that shape conscious visual experience.

Smooth pursuit ability is rare in the animal kingdom and only well developed in primates such as humans, and in praying mantises.

"It could be," Wilmer said, "that a penchant for high-level motion perception is essential for our incredibly handy ability to lock onto and examine moving objects."

Wilmer and Ken Nakayama, professor of psychology at Harvard University, reported their findings in the current issue of Neuron.

The research was supported by the National Science Foundation and the National Eye Institute.
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PostPosted: Fri Jul 06, 2007 9:37 am    Post subject: From the corner of the eye: Paying attention to attention Reply with quote

Salk Institute

From the corner of the eye: Paying attention to attention

5 July 2007

La Jolla, CA — Every kid knows that moms have “eyes in the back of their heads.” We are adept at fixing our gaze on one object while independently directing attention to others. Salk Institute neurobiologists are beginning to tease apart the complex brain networks that enable humans and other higher mammals to achieve this feat.

In a study published in the July 5, 2007 issue of Neuron, the researchers report two classes of brain cells with distinct roles in visual attention, and highlight at least two mechanisms by which these cells mediate attention. “This study represents a major advance in our understanding of visual cognition, because it is the first study of attention to distinguish between different classes of neurons,” says system neurobiologist John Reynolds, Ph.D., associate professor in the Systems Neurobiology Laboratory at the Salk Institute.

In the experiments, animals learned how to play a sophisticated video game, which challenged their visual attention-focusing skills. During the game, the Salk researchers recorded electrical activity from individual neurons in part of the visual cortex that has been implicated in mediating visual attention. (Please see video.)

http://www.snl.salk.edu/~jude/attentiontask.avi

As illustrated in the demonstration, the neurons respond when a stimulus appears within a window (indicated by the circle) covering a small part of the visual field that the eye sees. This window is known as the neuron’s “receptive field.” Whenever the stimuli entered the neuron’s receptive field, the cell produced a volley of electrical spikes, known as “action potentials”, indicated by vertical tick marks in the demonstration.

On some trials, attention was directed to the stimulus that entered the neuron’s receptive field, while on other trials attention was instead directed to the other stimuli. The researchers recorded almost 200 different neurons, and examined how each neuron’s response changed when attention was directed to the stimulus in its receptive field.

They found that neurons typically responded more strongly when attention was directed to the stimulus in their receptive fields. Upon closer inspection, however, the researchers noticed that different neurons produced different shaped electrical spikes: “broad spikes” and “narrow spikes.” Other researchers had previously identified two different types of neurons that produce these two waveforms. The most common neuron type, called a pyramidal cell, produces broad spikes. These neurons transmit signals between different brain areas. The other class, fast-spike interneurons evoke narrow spikes. These neurons only connect to their local neighboring neurons, and are involved in local computations.

After sorting the neurons by waveform, the researchers observed that attention had different effects on the two different types of neurons. The narrow-spiking cells typically fired more frequently when the tracked object was attended than when it was unattended. Broad-spiking cells, on the other hand, were less influenced by attention. Some fired faster, while others fired more slowly when attention was directed to the stimulus in the receptive field. What’s more, attention caused the stream of spikes produced by the narrow-spiking neurons to be much more reliable.

"By distinguishing among the different neural elements that make up the cortical circuit, we are gaining a view of the biological underpinnings of attention that is unprecedented in its level of detail," says post-doctoral researcher Jude Mitchell, Ph.D., lead author on the study. He adds that, while there is much more work ahead, "if we can understand how attention is acting on different cell classes, this will significantly improve our understanding of the pathology of neurological diseases in which attention is impaired."


###
Kristy A. Sundberg, a graduate student, also participated in the study.

The Salk Institute for Biological Studies in La Jolla, California, is an independent nonprofit organization dedicated to fundamental discoveries in the life sciences, the improvement of human health and the training of future generations of researchers. Jonas Salk, M.D., whose polio vaccine all but eradicated the crippling disease poliomyelitis in 1955, opened the Institute in 1965 with a gift of land from the City of San Diego and the financial support of the March of Dimes.
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PostPosted: Thu Jul 12, 2007 2:19 pm    Post subject: Link between carbohydrate quality and vision loss is strengt Reply with quote

Tufts University, Health Sciences
11 July 2007

Link between carbohydrate quality and vision loss is strengthened by new data

Friedman nutrition notes

BOSTON -- Age-related macular degeneration (AMD) and its associated vision loss may be connected to the quality of carbohydrates an individual consumes. In a study published in the July issue of the American Journal of Clinical Nutrition, Allen Taylor, PhD, director of the Laboratory for Nutrition and Vision Research at the Jean Mayer USDA Human Nutrition Research Center on Aging (USDA HNRCA) at Tufts University, and colleagues confirmed earlier findings linking dietary glycemic index with the risk of developing AMD.

"Men and women who consumed diets with a higher glycemic index than average for their gender and age-group were at greater risk of developing advanced AMD," corresponding author Taylor says. "The severity of AMD increased with increasing dietary glycemic index."

Glycemic index is a scale applied to foods based on how quickly the carbohydrates in foods are converted to blood sugar, or glucose. Foods like white rice, pasta and bread are examples of foods with a high-glycemic-index, meaning that these foods are associated with a faster rise and subsequent drop in blood sugar. Whole wheat versions of rice, pasta and bread are examples of foods that have a low-glycemic-index. These foods are often considered higher quality carbohydrates because they are associated with a slower and less dramatic rise and fall of blood sugar.

"Our results build upon findings from an earlier, smaller study in which we determined that consuming a diet with a high glycemic index, but not one with a high total amount of carbohydrate, increased the risk of developing early AMD," says first author Chung-Jung Chiu, DDS, PhD, scientist in the Laboratory for Nutrition and Vision Research at the HNRCA and an assistant professor at Tufts University School of Medicine.

In the current study, Taylor, Chiu, and colleagues analyzed data from 4,099 men and women participating in the nationwide Age-Related Eye Disease Study (AREDS). Detailed dietary histories were obtained at the start of the study when participants were 55 to 80 years of age and had varying degrees of AMD. The AREDS was designed to assess the effect of high-dose antioxidant vitamins and zinc on the progression of AMD and cataracts, two of the leading causes of vision loss in older adults.

"Although carbohydrate quality was not the main focus in the AREDS, we were fortunate that the investigators had collected the dietary carbohydrate information we needed to do our analyses," says Taylor, who is also a professor at the Friedman School of Nutrition Science and Policy at Tufts and the Tufts University School of Medicine. "Our findings suggest that 20 percent of the cases of advanced AMD might have been prevented if those individuals had consumed a diet with a glycemic index below the average for their age and gender," notes Taylor.

AMD typically occurs after middle age, although the events which cause it may begin earlier. A leading cause of irreversible blindness, AMD results from the gradual breakdown of light-sensitive cells in the central region of the eye's retina, called the macula. Although there is no effective therapy for AMD, dietary intervention may delay its progress. Identifying modifiable risk factors for AMD is becoming increasingly important as the population ages. As Taylor and colleagues point out, the number of people in the US with visually impairing AMD is expected to double and reach three million by 2020.

"Our results support our hypothesis," says Taylor, "that dietary glycemic index, which has been related to the risk of diabetes, is also associated with the risk and severity of AMD." Taylor speculates that carbohydrates that comprise a high-glycemic-index diet may provide eye tissue"It is possible that the type of damage produced by poor quality carbohydrates on eye tissue is similar in both diabetic eye disease and AMD."

Taylor and colleagues conclude that the risk for AMD may be diminished by improving dietary carbohydrate quality, as defined by dietary glycemic index. This may be achieved by relatively simple dietary alterations, such as replacing white bread with whole grain bread. "However," Taylor cautions, "additional studies are needed before we can recommend dietary carbohydrate management as a prevention strategy for AMD."

###
The study was supported by the U.S. Department of Agriculture Agricultural Research Service and by grants from the National Institutes of Health, Johnson and Johnson Focused Giving Program, the American Health Assistance Foundation, and individuals.

Chiu C-J, Milton RC, Gensler G, Taylor A. American Journal of Clinical Nutrition. 2007 (July); 86(1):180-188. "Association between dietary glycemic index and age-related macular degeneration in nondiabetic participants in the Age-Related Eye Disease Study."

The Gerald J. and Dorothy R. Friedman School of Nutrition Science and Policy at Tufts University is the only independent school of nutrition in the United States. The school's eight centers, which focus on questions relating to famine, hunger, poverty, and communications, are renowned for the application of scientific research to national and international policy. For two decades, the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University has studied the relationship between good nutrition and good health in aging populations. Tufts research scientists work with federal agencies to establish the USDA Dietary Guidelines, the Dietary Reference Intakes, and other significant public policies.
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PostPosted: Mon Jul 23, 2007 9:26 am    Post subject: Secret to Baseball's Best Hitters Revealed Reply with quote

Secret to Baseball's Best Hitters Revealed
By Corey Binns, Special to LiveScience

posted: 23 July 2007 09:34 am ET

Barry Bonds has his eyes on home-run history, but exactly why some pros excel at keeping their eyes on the ball has remained a baseball marvel until now.

Deciphering curveballs from fastballs and balls from strikes requires that a player's eyes precisely lock onto the ball, as described in recently published research on humans' ability to track balls and other moving objects.

"Our results show that individuals vary tremendously in this ability to lock their eyes onto a moving object, called smooth pursuit, and that this variation relates strongly to a specific type of motion perception ability, so-called high-level motion perception," said study co-author and University of Pennsylvania cognitive psychologist Jeremy Wilmer.

For the full article:

http://www.livescience.com/hea.....otion.html
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