Other than the second book that achrium posted, I haven't used a single book and it's not worth buying them until you KNOW that you have to. The library at the school you go to will probably carry any necessary textbooks. In general, I don't think it's a good idea to buy any books that aren't specifically optometry related.
Are you just trying to get an idea of how much text books will cost, or are you trying to actually purchase these books?