UV or ultra violet light/radiation is part of the invisible light spectrum that falls between 100 and 380 nanometers [nm]. UV light is divided into three ranges UV-A, UV-B, and UV-C. The range below 280nm is not considered a threat because most of it is filtered out by the earth’s protective ozone layer. Prolonged exposure to high range UV-A and UV-B radiation can cause significant eye damage ranging from discomfort to long-term vision problems such as cataracts. While clouds can block much of the visible light, nearly 80% of the invisible UV radiation can still reach your eyes. Lighter tint lenses do let more “visible” light into the eye; which is harmless, but lighter tinted lenses can still filter out 100% of the “invisible” UV light.