GI is a measure of how quickly food breaks down and delivers glucose to the body. It is easier for the body to process energy from food with a low GI measurement, meaning that glucose enters the bloodstream more slowly. Food with high GI scores include white bread and white potatoes, while whole grains, fruits and vegetables have lower GI scores, according to scientists from Tufts University.

The researchers conducted a study in mice in order to investigate the relationship between dietary GI and the negative effects of aging on the eyes. The subjects were divided into two groups, differing in diet quality.

Results showed that the mice that were fed a diet of low GI foods had healthier retinas, as published in the October issue of the journal Aging Cell. This may be because lower levels of glucose boost the performance of different cell pathways responsible for protein processing.

This experiment supports previous findings observed in epidemiological studies in humans, the researchers said.

A team of scientists from the University of Cambridge conducted a review of eight previous studies that examined the link between vision and time spent outdoors. The analysis included about 10,400 individuals. Results showed that children with normal vision were outside an average of 3.7 hours more per week compared to kids who were nearsighted, as reported Oct. 24 at the Annual Meeting of the American Academy of Ophthalmology.

The review did not find any link between nearsightedness and factors such as time spent on the computer or studying.

"Increasing children's outdoor time could be a simple and cost-effective measure with important benefits for their vision and general health" said co-author Anthony Khawaja. "If we want to make clear recommendations, however, we'll need more precise data. Future, prospective studies will help us understand which factors, such as increased use of distance vision, reduced use of near vision, natural ultra violet light exposure or physical activity, are most important."

Another potential study could address the question of whether the amount of time spent outdoors could halt the progression of nearsightedness.

One of the factors influencing the maintenance of good vision is ocular perfusion pressure (OPP). Low OPP can have negative effects on the eyes. A team of scientists from the University College London Institute of Ophthalmology decided to investigate whether physical activity had an effect on the two components of OPP: intraocular pressure (IOP) and overall blood pressure.

The researchers studied more than 5,600 individuals, aged 48 to 90 years, who were initially enrolled to participate between 1993 and 1997. At the outset of the study, subjects answered questionnaires detailing their physical activity at work or in their spare time. Results showed that about 15 years after enrollment, people who had moderate levels of exercise ultimately had healthier measurements of OPP, as published in the journal Investigative Ophthalmology & Visual Science.

"It appears that OPP is largely determined by cardiovascular fitness," said author Paul Foster, M.D., Ph.D., FRCS(Ed). When it came to certain conditions of the eyes, physicians thought the only factor they could have a direct influence on was IOP, according to the researchers. However, this study indicates that physical fitness can also have benefits for the eyes.

According to the survey, 53 percent of participants who have children age 18 or younger are concerned that 3D images may be harmful to their child's eyes. Additionally, 29 percent of respondents noted that they are very concerned about the potential damage.

"Today's classroom technology is extremely visual, making it critical for students to maintain excellent eye health," said James Sheedy, O.D., Ph.D., an AOA technology and vision expert.

"Binocular vision, focusing abilities as well as nearsightedness and farsightedness should be checked by an eye doctor yearly, particularly as students head back to school."

The survey shows that 10 percent of respondents' children experienced headaches, 7 percent reported nausea and 6 percent reported that their children felt dizzy after watching 3D images.

For their model, Michael L. Klein, M.D., and his associates used a large body of information containing analysis of physical, demographic, environmental and genetic circumstances pertinent to conditions affecting eye health. They compared approximately 9.3 years worth of data for patients who developed difficulties maintaining optimal vision in one eye to that of patients developing such issues in both eyes.

Among the 2,602 participants in the researchers' model, 24 percent of patients who had no pre-existing vision problems but were at risk for them developed impaired eyesight over the 9.3 years they were followed. Meanwhile, 82 percent of those who suffered from conditions detrimental to eye health at the beginning of the study developed further problems during that time.

The study's authors wrote that they hoped their research would help determine the necessary frequency of eye examinations for at-risk individuals and the viability of employing dietary tactics and nutritional supplements to promote eye health.

The Centers for Disease Control and Prevention states that a healthy diet, including the consumption of fish high in omega-3 fatty acids, may help maintain optimal vision.

A simple way to boost your eye health is by eating nourishing foods rich in antioxidant vitamins and minerals. Make it a habit to load your diet with foods packed with omega-3 fatty acids. And eat plenty of fruits and veggies that contain zeaxanthin and lutein, as well as whole foods containing zinc and vitamins A, C and E.

Some of the best eye-protecting foods include dark, leafy greens, apples, broccoli, brown rice, butterbeans, cabbage, carrots, cashews, chickpeas, coconut, grapefruit, grapes, green beans, lentils, mushrooms, onions, oranges, peaches, peanuts, pears, pinto beans, rolled oats, strawberries, sweet potatoes, tomatoes, walnuts, wheat pasta, whole grains and yams.

But you can also help preserve your eyesight by developing good lifestyle choices such as putting down the cigarettes—or never picking them up at all… minimizing your stress levels… exercising regularly… alleviating excessive eyestrain… and taking steps to promote healthy blood circulation.

Nutrients that may boost your vision include taurine, copper, bilberry, black currant, n-acetyl-L-cysteine (NAC), green tea, alpha lipoic acid (ALA), selenium and eyebright, as well as zeaxanthin, zinc and vitamins A, B6, C and E. With this combination of nutritious whole foods, healthy lifestyle choices and eye-supporting nutrients, you should see a difference in your visual health no matter what your age may be.

For this reason, U.S. health officials have recommended higher fruit and vegetable intake to help combat the growing number of people who develop serious health conditions.

In order to evaluate the effect that these programs have had on the actual amount of fruits and vegetables that Californians consume, a group of scientists recently conducted a 10-year study and published their findings in the Journal of Nutrition Education and Consumer Behavior.

They surveyed more than 1,400 California residents between 1997 and 2007. The study's results showed that the average daily number of fruit and vegetable servings rose from 3.8 to 5.2 during the investigation period. Moreover, the number of respondents who indicated that they ate five or more portions per day increased 57 percent by the end of 2007.

The researchers noted that sufficient fruit and vegetable consumption has been shown to provide valuable dietary nutrients as well as compounds that may promote good heart health and help ward off age-related vision problems.

According to a recent study published in the journal Cephalalgia, prescription glasses that provide custom tints may help reduce brain hyperactivity that occurs when an individual views a visually stressful light pattern, which often causes migraines.

The researchers explained that stimuli known to trigger migraines and epileptic seizures include patterns with high contrast stripes or gratings that can give the illusion of shape, colour and movement.

The participants were asked to use either a basic pair of tinted lenses or precision ophthalmic tints that had been created for the subjects' unique needs.

The study's results showed that participants experienced some level of of relief – 40 percent, on average – with all of the lenses. However, POTs were found to be the most effective since they yielded a 70 percent discomfort reduction when the subjects viewed stressful stripe patterns.

Tinted glasses may also help reduce migraine frequency by limiting the effects of harsh sunlight on the eyes.

According to a study presented during a meeting of the Vision Sciences Society, student athletes involved in football, basketball or soccer who used the strobe eyewear reported that they could see the ball more clearly because they could visualize its path and seem to witness the motion at a slower pace than usual.

The research involved more than 500 participants who wore the devices during training sessions. The goggles' lenses alternate between clear and opaque states at eight different rates, the investigators explained.

Subsequent computer tests revealed that some of the subjects were able to detect smaller amounts of motion or more discreet visual details than they were able to before the strobe training.

"Our results varied, but stroboscopic training does seem to enhance vision and attention. Not every test we tried showed differences, but several showed significant improvements," said lead researcher Stephen Mitroff.

Study investigators found that when the eye is exposed to temperatures below 30 degrees Celsius (C), the meibum, which is an oily substance that coats the eyeball, can harden and leave some areas without sufficient protection from wind or outdoor pathogens.

The substance may also clog meibomian gland ducts when in its solidified state. However, study results showed that once the eye reaches temperatures of 34 degrees C, the meibum rapidly returns to its original condition.

The study's author, Igor Butovich, Ph.D., offered a few tips for people who may experience dry eye symptoms.

"In cold climate, anything that keeps eyes and eyelids warm should help meibum flow easier, and form and maintain a better tear film; in windy conditions, protection from the wind—for example, with eye goggles—should reduce the tear film evaporation," he said.

Natural eye drop solutions may also help individuals relieve dry eye discomfort.