How Do Sunglasses Protect Eyes from UV Rays?
To understand how sunglasses work, you need to know what kind of harmful light they block. Ultraviolet (UV) light is simply a set of light rays too short to be seen by the human eye. There are three subsets of UV light: UVA, UVB, and UVC. UVB light is the type of light that is harmful to the human eye. UVB light may not be visible, but what you can’t see can harm you. If you undergo long or intense periods of exposure to UVB rays, several conditions can develop. People who fail to use protective eyegear in high UVB situations can develop photokeratitis, a condition where the eyes become sensitive to light and feel dry and sandy. Photokeratitis is also known as “arc eye” and “snow blindness,” reflecting the situations in which the condition develops, such as being exposed to the light from an arc welder or to reflected light from snow. You can also develop photokeratitis from reflected light from water or sand. Long-term exposure to UVB rays can also increase your risk of developing cat
