Anderson Cooper, while on assignment in Portugal, burned his retina so badly that he was blind for 36 hours. Cooper has since regained his vision and told his story on “Anderson Live.”

In the “Anderson Live” segment, Anderson Cooper recounts how he went temporarily blind in Portugal to his co-host Christie Brinkley. Cooper was in Portugal shooting a segment for “60 Minutes” and spent two hours on the beach, in the water, filming the “60 Minutes” segment. Cooper was already finished shooting for the day and was in bed when “I woke up in the middle of the night and felt like my eyes were on fire, my eyeballs.”

Cooper, at first thought his eyes were irritated -- maybe sand had gotten into his eyes since he had spent the day at the beach. After trying to wash out his eyes, to no avail, Cooper discovers what is really causing the burning sensation.

According to Cooper, he had sunburned his eyeballs, which led to his temporary blindness. He had to be treated at a hospital in Portugal and later posted photos on Instagram of his recovery. Copper posted a photo of his left eye being covered by an eye patch on Instagram and shared several more on "Anderson Live."

Cooper was not alone as Brinkley also had sunburned her eyes while skiing. In Brinkley's case, the snow acted like a mirror, reflecting the sun and the UV rays up into Brinkley's eyes. For Cooper, the water caused the UV rays to bounce up and sunburn Cooper's eyes. Cooper's eyeballs were even more susceptible because of their light color. NBC's Chief Medical Editor Nancy Snyderman, M.D., spoke to Cooper about the incident and reminded people to wear polarized sunglasses to prevent such accidents.

Video of Anderson Cooper discussing his temporary blindness on “Anderson Live” is below.