Millions of people turned out across America to watch the incredible total solar eclipse.
Most of them did so with some spiffy glasses like this:
They're designed to protect your eyes from permanent retina damage that can happen within 20 seconds.
Viewing the eclipse from the White House, US President Donald Trump wasn't so concerned:
Mr Trump took three glances at the eclipse without his protective eyewear, according to CNN, while onlookers in the crowd below shouted "Don't look!".
Perhaps they'd read the advice from Mr Trump's own US Department of the Interior.
Point number one on the department's tips for viewing the 2017 eclipse reads:
It is NEVER safe to look at the sun during the eclipse. Except during the very short period of totality do not look directly at the sun without approved solar-viewing devices.
Mr Trump took the advice of the concerned crowd member before too long, and slipped on his protective glasses for a look.
But a few seconds of the president looking up without his glasses was all social media needed:
