Don't mistake your optometrist for a mere optician. Optometrists are trained doctors who can perform detailed eye tests and dispense eyewear prescriptions; opticians basically just sell and fit eyewear. In Great Britain, some opticians provide both services, but they're vanishingly rare in the U.S.

Your first step in finding a good optometrist should be networking with your family, friends, and co-workers. They may be able to help you narrow down the field considerably, and point you in the direction of someone they trust. Try to get several options before you go optometrist shopping.

If you have diabetes, you should go to the optometrist at least once a year, whether you need new lenses or not. Diabetes can affect the chemical balance of the fluid in your eyes, which may negatively affect the quality of your vision; if this happens, you may need to get better control of your blood sugar.