Everyone is regularly exposed to UV rays. However, the dangers of long-term exposure to these harmful rays aren't really thought about, to a point where most people take little action to guard their eyes, even if they're planning to be exposed to the sun for long periods of time. Being exposed to too much UV is unsafe and cannot be reversed, and may lead to more than a few severe, sight-damaging diseases in older age. This means that ongoing protection from these rays is a must for everyone.
There are two types of UV rays: UVA and UVB, and both are unsafe. Even though only tiny amounts of UVA and UVB light enter the inner eye, the ocular tissue is very receptive to the dangerous effects of their rays. Even in the short term, small amounts of exposure may result in sunburn of the eye, often referred to as photokeratitis. When the cornea receives UVB rays, the surrounding cells are significantly damaged, and this can cause blurred vision, pain or in serious cases, temporary blindness. UVA rays can actually penetrate much deeper into the eye, which causes damage to the retina. Of the 20 million people who suffer from cataracts, about 20 percent of cases are partly caused by long-term exposure to UV rays.
A really great way to guard your eyes from UV rays is with quality eyewear. Check that your sunglasses or prescription glasses block both UVA and UVB rays completely. Wearing an insufficient pair of sunglasses can actually be more harmful than having no sunglasses at all. Consider this: if sunglasses don't give you any protection against UV, it means you're actually increasing your exposure to UV rays. Such sunglasses tend to reduce the light, which causes your iris to open and allow more light in. And this means that even more UV will be hitting your retina. It's important to check that your sunglasses give maximum UV protection.
Going out in a wide brimmed sunhat or cap will also block roughly fifty percent of UV rays. These hats will also reduce UV rays that reach 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 narrow, wedge-shaped tissue growth with blood vessels that spread over the white part of the eye's surface. In addition to being visually unsightly, a pterygium can cause discomfort, and can even change the contour of the eyeball, which will cause astigmatism. If the pterygium starts to grow over the cornea, it can blur or obstruct vision and may need to be surgically removed. Because pterygia are the result of extended UV exposure, it's entirely preventable.
Talk to your optometrist about the various UV protection options, including, but not limited to, fixed tint sunglasses, adaptive lenses and polarized lenses.