For most of human history people have lived without any protection from the sun for their eyes. Our eyes evolved to function with a great deal of exposure to the natural and unfiltered environment. Our brains developed to rely on the information that our eyes give to it about what is in the environment. However, the world is full of warnings about protecting your eyes from the elements. So this begs the question, is the sun harmful or beneficial to the actual organ, the eye?
The short answer is that both are true. Sunlight is absolutely helpful, and can also be harmful to the eyes. The following is a summation of some of the best information about both the good and the bad that comes with sunlight exposure.
UVB Is the Good UV
Both the New York Times and USA Today ran headlines recently that tout the benefits of sunlight on the eyes. It turns out, according to a study published in the Journal of the American Medical Association – Ophthalmology, that UVB decreases nearsightedness. The study looked at a number of European adults, age 65 and up, 10% of whom are nearsighted. They took the medical history of the subjects and correlated the results based on that and their examinations. Among those with vision issues related to nearsightedness, the large majority reported having the least exposure to UVB when they were in their teens and early adult years. The study determined that exposure in youth to UVB meant a 30% less chance of developing nearsightedness in later life.
Vitamin D and Your Eyes
The sun is also the best way to get vitamin D, which is actually created in the skin after exposure to sunlight. According to research published in Eye World, a publication serving eye professionals:
Vitamin D deficiency has been linked to numerous health problems, including type 2 diabetes, hypertension, and cardiovascular disease, and optic neuritis and myopia… Numerous studies have correlated vitamin D3 deficiency and other inflammatory diseases, including dry eye studies… In vivo studies (animal models) have shown vitamin D to be anti-inflammatory at the ocular surface, and in vitro vitamin D can lessen the inflammatory response to infection. Since the underlying cause of dry eye is inflammation, it makes sense that there could be an association between vitamin D deficiency and the disease… [and] physiological sense that vitamin D3 would also play a role in assisting with the inflammatory mediators in the tear film in patients suffering with dry eye.
There are many other benefits of sunlight related to your eyes, as reported in the British Journal of Ophthalmology:
The human eye contains photosensitive cells in its retina, with connections directly to the pituitary gland in the brain. Stimulation of these important cells comes from sunlight, in particular, the blue unseen spectrum. The effects are not only in the brain, but the whole body. Photosensitive cells in the eye also directly affect the brain’s hypothalamus region, which controls our biological clock. This influences our circadian rhythm, not just important for jet lag but for normal sleep patterns, hormone regulation, increased reaction time, and behavior… The hypothalamus also regulates the combined actions of the nervous and hormonal systems… The brain’s pineal gland benefits directly from the sun stimulation. The pineal produces melatonin, an important hormone made during dark hours that protects our skin. In addition, melatonin is a powerful antioxidant for body-wide use, is important for proper sleep and intestinal function, and can help prevent depression.
UV Radiation Can Damage Your Eyes
According to the American Academy of Ophthalmology, too much UV light exposure, or radiation, increases risks to the eyes.
Eye medical doctors (ophthalmologists) [warn of] cataract, growths on the eye, and cancer. Strong exposure to snow reflection can also quickly cause painful damage called snow blindness. Growths on the eye, such as pterygium, can show up in our teens or twenties, especially in surfers, skiers, fishermen, farmers, or anyone who spends long hours under the midday sun or in the UV-intense conditions found near rivers, oceans, and mountains. Diseases like cataract and eye cancers can take many years to develop, but each time we’re out in the sun without protection we could be adding damage that adds to our risk for these serious disorders. Babies and kids need to wear hats and sunglasses for this very reason. People of all ages should take precautions whenever they are outdoors.
The key for your eyes is balance. Natural light and sunlight provide clear benefits, but too much UV exposure, or looking directly at the sunlight, can do significant damage. You can make sure that you are protecting yourself by following your eye doctor’s suggestions that will be based on the amount of sunlight you individually might need and the environment you live in. You would also be well served by maintaining a good eye hygiene routine that includes using Cliradex for soothing relief of irritations that come with environmental factors.