The newsman went on to explain during Anderson Live that it happened when UV light bounced off a body of water, in turn sunburning his eyes.
"I wake up in the middle of the night and it feels like my eyes are on fire," he said. "It turns out I have sunburned my eyeballs and I go blind. I went blind for 36 hours. I took this picture of me after I went to the hospital."
"That's my new Match.com profile picture, by the way," he joked.
NBC medical editor Dr. Nancy Snyderman told Cooper that he was lucky.
The Silver Fox is no stranger to dangerous situations, though: He was attacked in Egypt last year during the protests against leader Hosni Mubarak.
"We were set upon by pro-Mubarak supporters punching us in the head," he said at the time. His crew tried to escape, but "the crowd kept growing, kept throwing punches, kicks... suddenly a young man would look at you and punch you in the face."