Summarize this article in one sentence.
Maybe your vision and your prescription haven’t changed at all, but your lifestyle has. For instance, have you changed professions and are suddenly spending more time outdoors or more time in front of a computer? In short, there are many types of glasses or lenses that are specifically useful for people who spend lots of time in one particular environment. Tell your eye doctor how you spend most of your time. This will allow them to help you choose the best glasses for you, considering your lifestyle. If you’re in love with your frames but worried that you might need to strengthen the lenses, don’t worry! You can often simply get new lens, as opposed to a whole new pair of glasses. You’ll need to visit your optometrist to specify your ideal prescription, and then mail your glasses off to a company that will measure and replace your old lenses with new ones. Many eyeglasses retailers will help you work through any issues with a new pair of glasses.  For instance, you may find that you new glasses are too heavy, or that a new prescription is especially bothersome.  In order to make sure you are not liable to additional expense, always ask something like, “If these end up not working out, will I be able to exchange them for another pair of glasses or lenses?” Note that there will be a short adjustment period after getting a new prescription. In fact, you may experience headaches for a short time, as you eyes and brain acclimate to the new glasses.  If discomfort persists, however, don’t hesitate to contact your optometrist.

Summary:
Account for lifestyle changes when choosing new glasses. Get new lenses in your old frames. Ask about satisfaction guarantees.