The FDA approved contact lenses that get darker in the sun, just like transition lenses you can get in glasses. The company that developed them, Johnson & Johnson, says they'll basically be invisible on people with dark eyes, and just slightly visible on people with light eyes. And luckily, no one who wears them will end up looking like a demon, or at least that's the claim (thanks to Buzzfeed News for clarifying).
They'll be called "Acuvue Oasys Contact Lenses with Transitions Light Intelligent Technology", and should be available in 2019.