What does vitamin A do? The name itself is a bit misleading, as it actually refers to a a group of closely related compounds – namely, retinal and four carotenoids, according to the Office of Dietary Supplements (ODS).

As the term may suggest, retinal is good for eye health, as it helps the retina absorb light, allowing it to detect low-level light sources and to differentiate between colors.

Carotenoids are similarly good for vision, and also act as antioxidants in the body, helping to prevent oxidative damage caused by free radicals.

These are just a few of the ways that the vitamin A complex helps improve well-being. The ODS notes that this group of nutrients also boosts immunity, assists in cell replication and contributes to bone health.

One of the best natural sources for vitamin A is the carrot. The Centers for Disease Control and Prevention states that one-half cup of carrots contains 270 percent of an individual's RDA of the nutrient. Vitamin supplements can deliver similar levels of retinal and carotenoids. 

What does vitamin A do? The name itself is a bit misleading, as it actually refers to a a group of closely related compounds – namely, retinal and four carotenoids, according to the Office of Dietary Supplements (ODS).

As the term may suggest, retinal is good for eye health, as it helps the retina absorb light, allowing it to detect low-level light sources and to differentiate between colors.

Carotenoids are similarly good for vision, and also act as antioxidants in the body, helping to prevent oxidative damage caused by free radicals.

These are just a few of the ways that the vitamin A complex helps improve well-being. The ODS notes that this group of nutrients also boosts immunity, assists in cell replication and contributes to bone health.

One of the best natural sources for vitamin A is the carrot. The Centers for Disease Control and Prevention states that one-half cup of carrots contains 270 percent of an individual's RDA of the nutrient. Vitamin supplements can deliver similar levels of retinal and carotenoids. 

A study published in the Journal of Neuroscience found that cells in the retina may be quite sensitive to vitamin C levels.

Researchers at the Oregon Health and Science University said that this effect is contingent of GABA-type receptors, which are neural gateways that help control the speed of rapid nerve communication.

The team found that goldfish denied vitamin C experienced a rapid decline in eye function. They noted that this phenomenon – the dependence of some neurons on vitamin C – may explain why diseases like scurvy sometimes result in depression.

"Maybe a vitamin C-rich diet could be neuroprotective for the retina," lead author Henrique von Gersdorff said. For those looking to maintain a high vitamin C level, oranges, strawberries and vitamin supplements may all serve the purpose.

Among Americans over the age of 60, MD is the primary cause of vision loss, according to the National Eye Institute (NEI). The condition occurs when the cells or blood vessels at the center of the retina begin to break down, which leads to increasingly blurry vision.

Experts have known for years that vitamin A affects the severity of MD. For instance, the NEI found that high doses of the nutrient – 25,000 international units – combined with large amounts of zinc and cupric oxide, prevented the onset of MD in aging patients.

Also, a new study conducted at the Columbia University Medical Center found that a special form of vitamin A, which contains an isotope of hydrogen called deuterium, may clump up less in the eye's small blood vessels. This effect could lead to better natural treatments for MD.

Taking a daily herbal supplement may put adequate levels of vitamin A toward good eye health.

According to the Centers for Disease Control and Prevention (CDC), AMD damages a person's central vision which affects the retina.

The researchers studied the amount of fish and shellfish—rich in omega-3s—that more than 2,300 participants consumed over one year. All of the subjects were between 65 and 84-years-old and completed an assessment that categorized them into four groups. These included no AMD, early AMD, intermediate-stage and advanced AMD.

Sheila K. West, Ph.D., the study's lead researcher, said that overall, the results "[corroborate] earlier findings that eating omega-3-rich fish and shellfish may protect against advanced AMD." She added that although all of the participants ate an average of one serving of fish or shellfish per week, those who were in the advanced stage of this disease were much "less likely to consume high omega-3 fish and seafood" compared to all of the other participants.

The CDC reports that nearly 2 million Americans who are at least 40-years-old suffer from AMD.

In research published in the journal Archives of Ophthalmology, more than 75 percent of children given acupuncture for amblyopia saw significant improvement in their visual acuity.

Between 0.3 and 5 percent of people worldwide have some form of lazy eye, according to the paper. Traditional treatments for it include corrective lenses and eye patches, which allow for the affected eye to strengthen its musculature.

However, even the combination of lensing and patching corrects just two in three cases of amblyopia, the study’s authors noted, adding that side effects of these treatments can include anxiety and the development of a second lazy eye.

After testing five acupuncture sites on more than 40 children between the ages of 7 and 12, researchers found that more than three in every four kids saw some improvement in their amblyopia.

While the mechanism of the treatment remains unknown, its efficacy exceeded that of traditional treatments over the 15-week trial. The study’s authors concluded that acupuncture may improve blood flow to the eye.
 

Researchers measured the eyes' electrical activity and the thickness of the macula, which is the part of the eye that processes light and controls central vision, in 13 women with anorexia. The team then compared the results to a control group of 20 female participants.

The results showed that the anorexic patients had developed thinner macula and nerve layers connected to this part of the eye. Also, the team discovered that women with the eating disorder had lower levels of electrical activity, which allows the brain to process images.

Because the team was unable to determine if these problems could lead to blindness, they concluded that future long-term studies will be needed to study how this may affect someone losing their vision. Furthermore, the investigators suggest that other research should monitor if returning to healthy eating habits could fix the damage.

Approximately 8 million people in the U.S. suffer from an eating disorder, according to South Carolina Department of Mental Health. 

Those who are deaf or blind have commonly reported that their other senses are more developed, but to determine the connection between these disabilities, investigators compared two groups of cats. The team analyzed the vision of deaf cats and compared them to animals that could hear.

The results showed that the deaf cats were able to better detect movement using their peripheral vision and had improved visual localization. Because of the efficiency of the brain, the researchers concluded that the organ compensates for the disabled sense by enhancing the abilities of others.

Stephen Lombar, lead author of the study, stated that "if you're deaf, you would benefit by seeing a car coming far off in your peripheral vision, because you can't hear that car approaching from the side." He added that "the same with being able to more accurately detect how fast something is moving."

An estimated 36 million adults in the U.S. have been diagnosed with some form of hearing loss, according to the Deafness Research Foundation. 

By improving blood sugar level control, researchers may be able to slow the development of diabetic retinopathy, which is retina damage caused by long-term diabetes.

In order to better understand this vision disorder, investigators enrolled 10,251 type 2 diabetes patients in the the Action to Control Cardiovascular Risk in Diabetes Eye Study. Participants were selected because they were at a high risk of suffering heart problems.

The team used treatments that could improve cardiovascular health in diabetes patients, including control of blood sugar, blood pressure and good and bad cholesterol in the blood.

The results showed that using these methods over the course of four years could slow diabetic retinopathy progression by approximately 34 percent.

Walter T. Ambrosius, lead author of the study, stated that cardiovascular problems in diabetics can "result in problems with the kidneys and amputation of toes and feet, and the only place that you can directly observe the microvasculature is in the back of the eyes." He added that "the eyes [are] potentially an indicator of what is happening in other parts of the body."

Approximately 1.6 million Americans aged 20 years and older are diagnosed with diabetes each year, the American Diabetes Association reports.

This eyesight disease leads to damage of the macula, where the central vision occurs. Individuals who are diagnosed with AMD can lose their peripheral vision, and in rare cases, develop blindness.

In an effort to determine how one’s diet affects the aging of their eyesight, researchers from the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston enrolled more than 4,000 individuals aged 55 to 80 years old in the Age-Related Eye Disease Study. During this trial, the team of participants were surveyed about what they eat on a regular basis.

The researchers discovered that people who consumed a slow carbohydrate diet, which includes foods containing compounds that naturally break down in the body slower than others, were less likely to suffer from AMD. Also, the results of the study showed that individuals who followed dietary regimens that included high levels of vitamin C, vitamin E, zinc, lutein, zeaxanthin and omega-3 fatty acids were better protected against developing eyesight programs.

Currently, more than 1.75 million Americans have been diagnosed with AMD, and because of the growing aging population, by 2020, the population is projected to increase to 3 million people, according to the National Eye Institute.