During the long, hot days of summer, you may find yourself reaching for your sunglasses to block the glare from the sun’s rays. You may not realize that donning shades does more for your eye health than just make it more comfortable to see. Blocking harmful ultraviolet (UV) radiation from the sun is good for your overall eye health and reduces your risk of developing cataracts.
A cataract is the clouding of the eye’s lens, which makes it hard to see. The lens is located behind the iris (the colored part of your eye) and the pupil (the opening in the middle of the iris). It works like a camera lens to focus light on the light-sensitive tissue at the back of the eye, known as the retina. The retina transmits lights signals to your brain to help process the image you see. Your eye’s lens can also change shape to help you see things far away or up close.
The cells in the lens are made up of mostly water and protein. The main proteins in the lens, called crystallins, work together to help the lens stay clear. When crystallins become damaged, discolored and clump together, a cataract forms. The large, discolored clumps of protein scatter the light that passes through the lens, preventing it from clearly focusing onto the retina. When this happens, your vision can become poor, dull or blurry.
The eyes are among the organs most easily damaged by UV radiation (the other is the skin). Long-term exposure to UV radiation or sunlight can damage lens proteins such as crystallins. Wearing sunglasses that block both UVA and UVB rays can reduce long-term sun exposure to your eyes and lowers your risk of developing a cataract.
If you notice your vision is getting blurry or colors start to look faded or you notice uncomfortable glares when you look at headlights or street lamps, visit your eye care professional to have your vision checked. In the meantime, remember to grab your shades before you hit the beach or hiking trail this summer.
Sadie Dierschke is a PhD candidate in the biomedical sciences program at Penn State College of Medicine. Her studies in the lab of Michael Dennis, PhD, include understanding how translational control of retinal gene expression contributes to the development of diabetic retinopathy.