One of the questions I am most frequently asked is how do I know what lens power I need in my reading glasses. Reading glasses lens power is determined by a few things. Using the scenario where you don’t have a distance correction, an easy starting point for choosing your lens power is to use your age as a guide. Around age 40 start with a +1.00 and towards age 50 a higher correction will probably work best. This age related principle is based on the old customary reading distance of 14-16 inches. It can still be used as a guide but in today’s computer dominated world, reading distances have changed. Sad but true most of us are not reading at traditional book reading distances (14-16”) but we’re holding reading material out further on our laps (I pad, cell phones, laptops) or at desktops where our reading distance can be anywhere from 18 inches to 32 inches. One lens power is not suitable for all reading distances. The principle behind this can be summed up most precisely in simple optical theory …focal power is inversely related to focal distance. Read through my explanation on how to choose the correct lens strength in your reading glasses, it will take the stress out of choosing the best correction in your reading glasses.