If too much sun exposure on unprotected skin can cause damage, wouldn’t it make sense to assume that the same can happen to eyes, as well?
Human eyes are incredibly susceptible to sun damage, in fact. Too much sun exposure can lead to photokeratitis, sometimes referred to as “snow blindness”, and affects more than just skiers and snowboarders.
On a trip to Portugal, CNN news anchor Anderson Cooper spent just two hours outside on a boat without any type of eye protection. The direct sunlight, along with the light reflected back off the water's surface, did severe damage to his eyes.
"I wake up in the middle of the night and it feels like my eyes are on fire... Anyway, it turns out I have sunburned my eyeballs," said Anderson. "I had no idea you could do this."
He was then effectively blind for the next 36 hours, but not all people who suffer from photokeratitis are so lucky. In most cases, with numbing and antibiotic eye drops for treatments, normal eyesight will return in just a few days. However, the effects are cumulative, with each instance of photokeratitis increasing the overall chance of developing cataracts or macular degeneration.
In order to prevent future damage, it's recommended to always wear UV blocking eye protection when outdoors.