Deciphering Your GlassesYou’ve just had an eye exam and received an updated glasses prescription. After looking at your prescription, you might be puzzled by the abbreviations and measurements. For example, what does OS or OD mean? What does a minus or plus sign indicate?Understanding how to read your prescription is easier than it looks at first glance. Once you know the basics, you can feel more confident the next time you discuss your new frames and lenses with your optician.Visual AcuityVisual acuity is a measurement of focusing ability at a set distance. In the US, 20/20 is considered normal visual acuity. The measurement is based on what an average person can see clearly at 20 feet.Suppose you have 20/40 vision. In that case, you must be 20 feet away to see an object the average person can see 40 feet away. Visual acuity indicates visual clarity, but it doesn’t measure other crucial vision skills, such as depth perception, eye coordination, or peripheral (side) vision.Vision test...
