“How can I choose the right reading glasses?”

The right answer is to go and have an exam. Make sure your eyes are healthy, and that there is none of the silent diseases that can cause problems. If you have to buy over the counter glasses, the doctor should be able to make a recommendation. Over the counter glasses are meant to be, an any port in the storm solution. For your day in day out reading , everyone should have a proper pair made for themselves. Having them made for you will make sure they are right for you, and then you have someone to service them, adjust them, and make sure they fit you correctly.

Best way is to just go to the drug store and try on a few different powers and see what reading distances are most comfortable. Choosing the "wrong" power won't hurt your eyes, but can cause temporary eye strain and headaches. In general, the higher the power (e.g. +3.00 vs +2.25) means that the focusing distance is closer to your face than the lower power. So, for computer use, you may like a +1.50 but for reading a phone up close you may want a +2.00 for example. If nothing seems right, then go to the eye doc to get a formal refraction and then you'll get a customized pair of readers that should be perfect for you.
Hope that helps.

Depends on age . Ask your doctor

A complete eye exam can help determine the best prescription for reading glasses.