6:11am PT by Hilary Lewis
Sochi: Meredith Vieira to Make Olympic History Filling in for Bob Costas (Video)
Meredith Vieira is set to make history by filling in for a still-ailing Bob Costas on Friday night's primetime Olympics coverage.
The former Today host is the first woman to anchor NBC's primetime coverage of the games solo.
Costas is still battling an eye infection that's plagued him from the start of the games and has since spread to both eyes and affected his vision, with the legendary sports broadcaster previously saying he can't be in the studio.
Matt Lauer had filled in for Costas since Tuesday night, which marked the first time since 1988 that Costas did not host NBC's primetime Olympics coverage.
Olympics executive producer Jim Bell told Today.com on Thursday, "Bob’s eye issue has improved, but he’s not quite ready to do the show. If your eyes are sensitive to bright lights, a TV studio is not the place to be."
On Thursday, Costas told Ryan Seacrest's radio show that he will return to NBC's Olympics coverage, saying he hoped he'd be back by the weekend or at least the second half of the Games.
"In sports, there's a term that they use for people who are on the injured list -- they say, 'He's day-to-day.' And I am day-to-day," Costas said. "I'm hoping that I'm back by the weekend, and I certainly think I'll be able to do the second half of the Games. The virus, they tell me, won't run its course for two or three weeks, but the symptoms will crest at their worst and start to get better pretty soon. As soon as the symptoms get to the point where I can be in the studio, I'll be there."
Costas confirmed that the infection was interfering with his vision and exacerbated by studio lights.
"It got to the point my vision became so blurry and sensitive to light, I can't even be in regular room light, let alone studio light. I couldn't be of any use to them."
Vieira, who formerly co-anchored Today with Lauer, has been contributing to NBC's Olympics coverage, co-hosting the Opening Ceremony last week.
Although Hannah Storm, Jane Pauley, Mary Carillo and Gayle Gardner previously hosted NBC's daytime and late-night Olympic coverage, Vieira is the first woman to do so solo for the network in primetime.
Lauer, meanwhile, seems exhausted by having to host Today and nighttime Olympics coverage for the past three days.
"I'm dragging a little today. I didn't sleep at all since yesterday morning," he told Today.com on Friday. "Meredith's fantastic. She'll be great, she really will, and I know she's going to have a blast. It's fun!"
What will Lauer be doing tonight?
"Sleep, sleep, sleep, that's my night tonight," he said. Lauer also said on Friday's Today that Vieira may fill in for Costas again on Saturday night.
Lauer previously told The New York Times that he expected to get a day or two off even if Costas wasn't able to return.
“I can’t do this schedule for any prolonged period of time,” Lauer told The Times. “I don’t want the fact that I’m doing double duty to impact the way we do the Today Show.”
Bell also told The Times that he considered the possibility that Costas would not be able to do any more Olympics broadcasts this year, but he declined to say if Al Michaels or Dan Patrick, who are anchoring other parts of NBC's Olympics coverage, will fill in for Costas.
As with previous substitution announcements, Friday's switch was made on Today, where Vieira was absent, already going to bed for her primetime gig.
When she called in, she joked that she, too, was having eye problems, after having watched an earlier segment in which Lauer and Al Roker attempted the luge.
"I woke up this morning and I was feeling fine and now my eyes are killing me! I watched you guys attempt the luge and I think I'm going blind. And I'm really worried because I have to host primetime tonight," she said.
Vieira also joked that in terms of sleep, she'll probably pass out at the bar.
During the segment, Savannah Guthrie added that Costas said he hopes he'll be back soon. "Otherwise, he'll have to call Kathie Lee and Hoda to come and fill in."
Watch the video of the announcement on Today below.