My last eyeglass prescription was from the My Eye Doctor chain, and it had a one-year expiration on it.
I'd never paid attention to them at any time in the past, and I only noticed that one when I decided to order a cheap pair online to get me through till my cataract surgeries. Got 'em just in time. Although I don't think I had to show them the actual prescription, I just copied everything into the online forms.
Anyhoo, yes, they sometimes (or often) have expiration dates.