Tesla CEO Elon Musk may have taken a big risk watching the eclipse on Monday.

Musk said via Twitter that he watched the solar eclipse wearing sunglasses through the glass roof of his Tesla Model S.

Watching eclipse with sungl... @ Elon Musk

It's not clear whether Musk meant eclipse sunglasses or actual sunglasses, but if it's the latter, he could have done some serious damage to his eyes.

As my colleague Kevin Loria pointed out, without wearing the proper eyewear "Ultraviolet light from the sun can penetrate and be absorbed into your retina, causing a condition that eye doctors call solar retinopathy."

Solar retinopathy is damage caused to your retina by the sun and can either be temporary or permanent.

Check out the full list of eyewear that is safe to wear during an eclipse here.