Readymade reading glasses are widely available in pharmacy outlets, supermarkets and even some large bookshop chains. Compared to spectacles sold by a dispensing optician they are inexpensive and you do not have to wait for them to be made for you. However they are of limited value in that you can only judge how effective they are by trying them on and reading something in a shop. Lenses and frames made and bought at a dispensing opticians are the final part of a process that includes a systematic eye test and an inspection to screen you for a range of eye diseases. The test takes account of your particular needs and circumstances. The correct lens prescription is likely to cause you less eye strain while the frames will be fitted to ensure that you get the optimal use of your lenses. Compared with this, hobby glasses don’t take into account any differences there may be between your left and right eye, astigmatism, nor the correct centration of lenses which can sometimes induce double vision.