Since I've worn glasses from the time I was 16, I've been curious as to what hosts wore glasses, and why. I'm going to note a few from what I remember, and please feel free to add/correct my information.
- Bill Cullen wore glasses virtually from the time we first saw him (although I think there are a few publicity stills from when he was very young without them).
- Groucho Marx wore his throughout the run of You Bet Your Life; it looks like he started wearing them years before.
- Allen Ludden also appears to have worn glasses his adult life, as he's shown wearing them in a still photo for Mind Your Manners.
- Peter Marshall started wearing glasses partway through the run of Hollywood Squares, maybe around 1970 or 1971 (although he has them on for a Kellogg's commercial before that series started). My guess is Marshall is farsighted, as you almost never see him wearing glasses during show intros; only during the gameplay.
- Tom Kennedy looks to have added glasses during the run of Split Second.
- Larry Blyden wore glasses for all his hosting duties; he seems to have not worn them or gone to contact lenses for some of his acting roles as needed.
- Jim Lange added glasses during the run of The Dating Game.
- Alex Trebek started wearing glasses around 1990 or so.
- Drew Carey got LASIK at some point but kept the glasses as a prop, but he now needs bifocals. (I hear ya, Drew.)
Any others?