OD refers to the right eye and OS means the left eye if you have an identical prescription in both eyes, you might see the letters OU. These numbers usually stay relatively low, beginning at +0.75 and ending around +3.00.įinally, you may be wondering what OD and OS mean. Near reading strength numbers for people requiring bifocals for reading. Each eye can have several prism numbers depending on the prescription An additional number followed by a symbol, such as 2^, indicates prism correction. However, some people have additional abnormalities that must be corrected to achieve perfect vision. We’ve just described what the numbers can look like for three of the most common types of refractive errors. Because astigmatism causes the lens to be football- or somewhat cone-shaped as opposed to perfectly rounded, it is measured in degrees in this case, the astigmatism has a 90-degree orientation.Īdditional numbers and letters in an eyeglass prescription The last number relates back to the astigmatism.Not everyone has astigmatism, of course, so if the number wasn’t there, you’d see some letters – DS or SPH – to indicate that there is no astigmatism. This second number, -0.75, indicates the person has an astigmatism, which is a distortion in the shape of the cornea that causes blurred vision.
WHICH IS RIGHT AND LEFT OD OR OS PLUS
A plus sign would mean they are farsighted. Because there is a negative sign in front of the 4.50, that means the person is nearsighted (quite nearsighted actually!). The -4.50 describes the spherical refractive error, which is either farsightedness or nearsightedness.For a person whose prescription is -4.50 -0.75 x 90, here is what those numbers mean: That’s great news if you find yourself stranded on vacation with damaged glasses – we recommend that you always carry a copy of your most current prescription in your wallet, so local opticians will be able to craft a new pair for you if necessary.Īn eyeglass prescription can contain several different numbers – no wonder it’s confusing. Eyeglass prescriptions are standardized worldwide
Here, we’ll demystify the eyeglass prescription so you can finally know for sure what the numbers mean.
Sound familiar? While you don’t really need to understand your eye prescription, in the sense that you don’t really need to understand how electricity works in order to use it…it’s definitely good to know what is going on with your eyes so you can track any changes, spot any mistakes, and understand what your prescription means to your day to day vision. At no time do you understand any part of the process.
You take it, without even looking at it, straight to your optician, who uses it to make your next pair of lenses. After your eye exam, the doctor hands you a small slip of paper covered with confusing numbers.