Everyone is regularly exposed to UV rays. But the potential risks of many years of exposure to these harmful rays are not often considered, to a point where most people take little action to guard their eyes, even when they're expecting to be exposed to the sun for long periods of time. Being exposed to too much UV is dangerous and cannot be reversed, and may lead to more than a few severe, sight-stealing diseases in older age. And so, continuing protection from UV rays is extremely important.
There are two types of UV rays: UV-A and UV-B, both of which are damaging. Even though only minimal measures of UVA and UVB light hit the inner eye, the eye cells are extremely vulnerable to the damaging effects of their rays. Even in the short term, small amounts of exposure may lead to sunburn of the eye, or photokeratitis. When UVB rays are absorbed by the cornea, the outer cells are destroyed, which can lead to pain, blurred vision or temporary blindness. UVA rays actually permeate the eye much deeper, which causes damage to the retina. Of the 20 million people suffering from cataracts, about 20 percent are partly caused by extended exposure to UV rays.
One of the best ways to guard your eyes from UV rays is through the use of quality sunglasses. Be sure that your sunglasses or prescription glasses block 100 percent of UVA and UVB rays. An inadequate pair of sunglasses can sometimes be worse than having no sun protection at all. Consider this: when sunglasses offer no protection against UV, you're actually being exposed to more UV rays. Sunglasses that are inadequate generally reduce the light, causing the iris to open and let even more light in. And this means that more UV will reach the retina. Always check to make sure your sunglasses provide enough protection against UV.
Wearing a large hat or cap will also block about half of UV rays. A brimmed hat or cap may also reduce UV rays hitting your eyes from above or around glasses.
Extended exposure to UV rays can also lead to an abnormal tissue growth on the eye, known as pterygium. This is a slim, wedge-shaped tissue growth with blood vessels that spread over the white part of the eye's surface. In addition to being cosmetically unappealing, a pterygium can be uncomfortable, and can even alter the contour of the eyeball, which will cause astigmatism. If the pterygium begins to grow over the cornea, it can affect vision and may require surgery. Because pterygia are caused by extended UV exposure and windy conditions, it is completely preventable.
Speak to your eye care professional about all the different UV protection options, including adaptive lenses, polarized lenses and fixed tint sunglasses.