Convert Your Eyeglass Prescription: How to Add Power for Effective Reading Glasses
To convert ADD power to reader strength, add your SPH (Sphere) value to the ADD value. For example, if your SPH is +1.00 and your ADD is +1.75 for your right eye, the total strength of your reading glasses will be +2.75. This calculation method helps you find the correct prescription lenses for your visual … Read more