Is it practical for the visually-impaired to play in casinos?
If you play table games like blackjack, I don't think you'd have any trouble (although since only a card counter would want to know other people's cards, don't expect any help there. ;)).

In Hold-'em poker, some seats are definitely better than others; the cards generally go right in front of the dealer, so if you can get the seat directly in front of the dealer you'd probably be fine, and you might be able to make do with the seats on either side of the dealer depending on how small the tables are. I suspect that in the worst case you could tell the floor that you can only play in the center seat, and see how well they can accommodate you. If the room's even halfway decent they'll try to take care of you.