The total solar eclipse on Aug. 21, 2017, is kind of a big deal.
Depending on where you are in the US, you'll see either a partial or total eclipse.
But there's a catch. Looking directly at the sun — even when it's partially blocked by the moon — is dangerous.
Other than the brief moment when the moon completely blocks the sun (if you're in the path of totality), the eclipse must be viewed with special solar filters that are certified to meet international safety standards, says Fienberg. (More on those and eclipse-viewing safety shortly.)
So, what exactly happens when you look at the sun? Turns out that although you probably won't go totally blind, you can get super-serious, permanent eye damage in less than 30 seconds. Yikes.