GLASSES AS GIFTS?

My wife found a website that only sells glasses over the internet. These are prescription glasses, mind you, and they are inexpensive to boot. No overhead will do that for a business. At any rate, she has an interest in buying a nice pair for her father from zennioptical.com because he has had the same pair for quite some time. Eye insurance isn't something that everybody carries and she thinks he would appreciate a new pair. She has answered the question of, "What do you buy someone who has everything?"

My question, however, is how does one pick out a pair for a loved one? Do we let the cat out of the bag and tell him what his gift will be so he can pick out the pair or do we buy the pair we think look nice? Ah, it's her father; she can figure it out.