A prescription can not help to determin what a patient's overall visual acuity is. Your visual acuities are determined based on a test using the Snellen chart at a distance of 20 ft. Your VAs are also different "corrected" or "uncorrected", one meaning with your glasses and the later meaning without your glasses on. Those numbers will be different. Ask your eye care provider for the information that your doctor obtained during your examination. Thank you.