You need to buy a new pair of eye glasses in the store or eye glasses online:
* Every time your prescription changes
* You're tired of your old eyeglasses
* Your glasses go out of style and you need to buy new eyeglasses online
* Your face shape changes, e.g. after surgery or changes in weight.
* Your hair color changes
* Your eye doctor makes recommendations—you should generally see your eye doctor once a year or once every two years.