Your prescription for eyeglasses says a lot about you. That series of letters and numbers can instantly tell a professional the type of vision problems you experience. Here are answers to a few common questions to help you decode your prescription. 

What You Should Know About Eyeglass Prescriptions

How do they mark nearsightedness and farsightedness?

Prescriptions for nearsighted  people can be identified by the minus signs in front of the numbers, while farsightedness prescriptions have plus signs. The higher the number, the greater the corrective power required for either purpose. For example, mild nearsightedness might result in a prescription of -0.50, while more extreme cases could show -4.25. 

What if I have astigmatism?

The C stands for “cylinder,” and it measures the severity of your astigmatism in units known as diopters. The higher the number, the more irregular your cornea is.

The axis will fall between 0 and 180 degrees, denoting the angle of your astigmatism.

Add is the amount of magnification applied to the bottom area of your lenses to help you see better.

How can I tell which numbers relate to which eye?

Your prescription will have two parts, marked by “OD,” followed by a series of numbers, and “OS,” followed by more. OD represents the prescription for the right eye, while OS is the left eye.

Can I use this to buy contact lenses?

While you might assume they are one and the same, eyeglass prescriptions are far different from ones for contacts. This is because glasses sit away from the eye, while lenses are placed directly against the cornea. The inch or so between these points significantly affects the magnifying power you’ll need to see clearly.

If you’re looking for new eyeglasses, head to Cohen's Fashion Optical in Manhattan’s Upper West Side. They’ve been helping New York City residents since 1927. They are focused on providing high-quality products at affordable prices. In addition to eyeglasses and sunglasses, they also prescribe contact lenses to meet your needs. Visit their website to learn more about what they do, or call (212) 769-1410 today to schedule an eye exam.