Written by: Rusa Tskitishvili

The U.S. Food and Drug Administration approved the first contact lenses that can act like sunglasses.

A special additive automatically darkens the lenses when exposed to bright light, while they become clear again in normal or dark lighting conditions.

The FDA's approval was based on research that included a clinical study evaluating daytime and nighttime driving performance among 24 people wearing the contact lenses. There were no problems with driving performance or vision while wearing the contact lenses, the study found.

The FDA did note that certain patients should not use these contact lenses. They include people with inflammation or infection in their eyes, those with eye diseases or eye injuries, and those who have severe dry eye or allergic conditions that could be exacerbated by wearing the special lenses.