Did you know that UV can damage your eyes?
Light entering the eye penetrates through different levels the same way it penetrates your skin. Two different types of light enter the eye, namely UV light and Visible light. Fortunately we have the cornea and the crystalline lens to reduce the amount of UV rays entering our eyes, minimizing the amount of UV reaching the retina.
Some structures around the eye, like lids, lashes, eye brows etc, also provide some form of protection against UV. When visible light penetrates the eye, it falls on the retina and stimulates photoreceptors in order to produce an image. Visible light (not UV radiation) causes pupil constriction, eyelid closure and squinting can reduce penetration of the sun’s rays on a sunny day. On cloudy days, visible light is minimized but the exposure to harmful UV rays is still high.
Visible light increases the risk of macular degeneration and UV light increases the development of cataracts. Many people forget that the greater the exposure to UV radiation, the greater damage caused over a sustained period of time. But UV light isn’t all bad; we certainly need it for Vitamin D production. Vitamin D helps in strengthening bones, protects us against diseases, helps to increase calcium and phosphorus absorption from food, and enhances blood circulation.
3 Types of UV Rays Exist:
UVA – Penetrates into deeper skin layers where connective tissue and blood vessels are affected. The crystalline lens absorbs UVA to help protect the retina. With pigment accumulation in the lens, age and a lifetime of UV exposure cataracts are very likely to develop. Fortunately cataracts can be removed and vision restored with an artificial lens. After surgery this form of surgery, UVA light can penetrate the eye with greater ease and therefore post-op UV protection is essential.
UVB – Causes sunburn and ‘snow blindness’ from reflection of water and snow, increasing likelihood of cancer. Light reflection off snow, water and sand increases the amount of UVB penetrating the eye. The cornea protects the eye against UVB but the conjunctiva stays exposed. UVB radiation can lead to the development of pterygiums and penqueculas; these are little white elevated tissue growths on the conjunctiva. They are not sight threatening, but can become uncomfortable, red and unsightly when exposed to the elements. In severe cases they may lead to corneal problems and result in distorted vision. Surgical removal is possible.
UVC – is filtered by the ozone layer and has the highest energy UV rays, they are the most harmful to your eyes.
How can you protect your eyes from the sun?
Spectacles with UV-coatings, sunglasses, large brimmed hats and visors are some measures you can employ to protect you from the dangers of UV. Clear prescription spectacles (without a UV coat) do provide some form of protection but not protecting the full 100% and you remain at risk.
- Date July 26, 2018
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