How to find my prescription from my glasses if i lost the paper slip?

Check with your doc: You were probably given a prescription for eyeglasses when you last had your eyes examined. If you can't find your prescription, you can check with your doctor's office -- there should be a copy in your chart. (another reason medical records are useful!) eyeglass stores often have a machine that measures the refraction of your current eyeglasses, and may be able to use this for sunglasses.