You're getting too much sun.
Some people develop a yellowish patch or bump on the whites to the side of their iris, called a pinguecula. "A small percentage of these are pre-cancerous, but usually they are not," Herz says.
What causes them? "They are most often seen in people who spend a lot of time in the and are similar to a callus on the skin," she adds. But a looked at ultraviolet light's effects on the eye and found that wearing specific lenses may protect your peepers from , so talk to your ophthalmologist if you start seeing the patches.