Ultraviolet (UV) light is an invisible, electromagnetic radiation. Your exposure to UV rays comes primarily from the sun, even on a cloudy day. The sun emits UV rays, and unprotected, prolonged exposure can cause serious vision problems. Many Americans do not understand the dangers of UV exposure and take needless risks with their eyesight. The Vision Council’s VisionWatch survey of more than 10,000 adults shows Americans are concerned about potential eye problems from the sun’s UV rays, yet they have a passive relationship with UV-protective sunglasses.