Costas has been wearing glasses since the start of the Sochi Olympics because of an infection in his left eye. On Monday's broadcast, it was apparent the infection had spread to his other eye. It quickly became the topic of conversation on social media and sports talk radio.
No one else has anchored a prime-time summer or winter Olympic broadcast in the U.S. since 1998, when CBS had the rights to broadcast the games.
Costas called in to the "Today" show Tuesday to talk to Lauer and said, if anything, his eyes had gotten worse.
"I was trying to throw a complete game here, but I think we're going to have to go to the bullpen, and I don't know if you're aware of this or not, but you're Mariano Rivera, at least tonight," Costas said. "Let's hope it's only tonight. I'm walking around, I might as well be playing 'Marco Polo.' I have no idea where I am."
On NBC's late-night telecast, he shared a vodka toast with correspondent Mary Carillo and said, "I'm looking at it this way ... my eyes can't get any redder."