text: can you take a prescription from an existing pair of glasses? i don't need a new eye test as the glasses i have are perfect, just the style is out of date. the eye doctor can look at your glasses and tell you the prescription that they are so you can get a new pair.  or, if you pick out a new frame that will fit the lenses you have, you can have them trimmed to fit and that way you can save some money as you won't have to buy new lenses.  but, if it's been more than a year or two, the doctor may have you take a new exam anyway.  i have to do it every year to get my contact perscription refilled even though the scrip hasn't changed in over 5 years.