How to Read an Eye Prescription: What the Numbers Mean

even eye exams are an authoritative region of keeping your eyes goodly and your sight sharp. At your eye examination, an center doctor, optometrist, or ophthalmologist, will check for any signs of center disease. If your vision needs to be corrected, you ’ ll be given a prescription for eyeglasses or contact lenses. eye prescriptions can be hard to decipher, though. They normally contain an assortment of numbers and letters that can be confusing if you don ’ t know what they mean. This article will help make sense of the abbreviations and numbers that may be included in your eye prescription. It will besides explain how prescriptions can vary depending on your sight emergence.

About eye prescription abbreviations

Your monocle or touch lens prescription will contain respective abbreviations, many of which will be followed by numbers. here ’ s a compendious of what these abbreviations mean :

A glossary of eye prescription abbreviations

  • ADD stands for the additional lens power needed to make it easier for you to read. This number is seen on prescriptions for reading glasses or the lower portion of bifocal or progressive lenses.
  • Axis is a number between 1 and 180. It indicates exactly where the astigmatism appears on your eye.
  • BO, BI, BU, BD stand for base out, base in, base up, and base down. These abbreviations tell the eyeglass manufacturer exactly where to position the prism on eyeglasses that correct double vision.
  • CYL stands for cylinder, or the amount of astigmatism in your eye. The cylinder and axis together help correct astigmatism.
  • DV is an abbreviation for distance vision. This number indicates whether you have nearsightedness or farsightedness.
  • NV stands for near vision, or the amount of power that needs to be added to make reading easier.
  • OD means oculus dexter, or your right eye.
  • OU stands for oculus uterque, or both eyes.
  • OS is oculus sinister, or your left eye.
  • PD means pupillary distance. Monocular PD is the distance from your pupil to the middle of your nose. Binocular PD is the distance from one of your pupils to the other pupil.
  • Prism is used if you have double vision. It indicates the amount of prismatic power your glasses need to correct for differences in the alignment of your eyes.
  • SPH means sphere, or the power of the lens that will correct your eyesight.

What about the numbers?

many of the abbreviations on your prescription will be followed by numbers. If the numbers are marked with a plus signboard ( + ) or no signal, you ’ rhenium farsighted. If the numbers are marked with a minus gestural ( – ), you ’ re nearsighted. Some of the numbers in your prescription tell the monocle manufacturer how much correction your sight needs. Eyeglass persuasiveness is measured in diopters. If your prescription reads -1.00, that means your eyeglasses need 1 diopter of persuasiveness to correct myopia. If your prescription reads +2.50, your eyeglasses need 2.5 diopters of military capability to correct prevision. The higher the number, the more correction your imagination needs.

What to know about nearsighted prescriptions

Nearsightedness, or myopia, is a common deflective disorder. If you ’ ra nearsighted, you can see objects that are close intelligibly, but objects that are farther away will look bleary. With myopia, your eye is normally elongated, with excessively much distance between the cornea at the front of your eye and the retina at the back of your eye. Nearsightedness can besides happen if the cornea of your eye is excessively curved. due to this increased distance, faint rays fall in presence of your retina ( a light-sensitive structure that sends signals to your brain ) rather of on it. This can cause your distance imagination to be fuzzy. The lenses in your eyeglasses will correct the bend in the faint and assistant you see distant objects more clearly. For a nearsighted prescription, the potency of the lenses will be marked with a minus sign. The more nearsighted you are, the higher the numbers will be. For exemplify, a lens prescription of -5.00 is a stronger prescription than -2.00. The forte of the lenses can vary for each eye.

What to know about farsighted prescriptions

Farsightedness, or hyperopia, is a refractive disorder that makes airless objects harder to see than distant objects. It happens because the distance from the cornea to the retina is besides short or because the cornea of your eye is not curved adequate. If you ’ re farsighted, sparkle focuses behind your retina rather of squarely on it. For a farsighted prescription, the force of the lenses will be marked with a asset bless. The more farsighted you are, the higher the numbers will be. For exemplify, a lens prescription of +4.50 is a stronger prescription drug than one that ’ south +2.00. Correcting your vision with glasses or contact lenses, for both myopia and presbyopia, may besides help prevent :

  • headaches
  • eye strain
  • burning or stinging in your eyes

What to know about astigmatism prescriptions

Astigmatism is an atypical bend in either the lens or the cornea of your center. This irregular curvature can bend the light that enters your center and affect the way it hits your retina. astigmatism can blur both cheeseparing and far objects. It can besides distort the images you see. astigmatism is not strange. In fact, The american Academy of Ophthalmology reports that 1 in 3 people have the condition. If your astigmatism measures 1.5 diopters or more, you may need to wear prescription glasses or reach lenses to see properly. That said, if you have any amount of astigmatism, you may appreciate the extra clearness of wearing prescription eyewear. Your prescription drug will indicate how dangerous your astigmatism is and where the irregular curve appears on your eye.

Other lens recommendations

Your monocle prescription might besides include notes from your optometrist or ophthalmologist about other features of your glasses or contacts. Your lenses might :

  • be progressive or bifocal, meaning they correct for both distance and close-up vision.
  • have an anti-reflective or anti-glare coating to reduce glare to make it easier to see at night or when working on a computer
  • be photochromic, which means they darken or lighten depending on the lighting conditions around you
  • be treated with a coating to make them more scratch-resistant

Yes. Because contact lenses sit directly on the come on of your eye, they need to have the same curves as your eye.

A reach lens prescription contains measurements for :

  • Base curve: a number usually between 8 and 10 that conforms to the shape of your eye
  • Diameter: the distance from one side of the lens to the other, usually around 13 to 15 millimeters

Your contact prescription besides identifies the trade name and type of lens, along with an passing date. Contact prescriptions have to be updated from year to year to account for changes to your vision and to ensure they fit properly.

How often should you see your eye doctor?

The American Optometric Association recommends that you have an eye examination at least every 2 years if you ’ re under 60 and every year if you ’ re over 60. It ’ second crucial to have your vision and eye health checked regularly because some serious eye conditions, such as glaucoma, don ’ t have noticeable early symptoms. An eye doctor can test your eyes and detect changes early, which may prevent imagination passing. The tests are quick and painless, and can besides help detect the watch eye conditions :

  • cataracts
  • glaucoma
  • age-related macular degeneration

Eye exams can besides indicate when another health circumstance, such as diabetes or high blood pressure, may be affecting the health of your eyes.

The bottom line

The abbreviations and numbers on your monocle prescription tell the monocle manufacturer what character of lenses you need and how hard they need to be. This data besides indicates the degree of myopia, prevision, or astigmatism in each of your eyes. Because contact lenses sit directly on the surface of your center, they need extra information, such as the base and curvature of your eye. Your monocle or liaison lens prescription international relations and security network ’ t a one-and-done situation. Over time, your vision can change, so it ’ south important to see an eye doctor of the church at least every copulate of years to protect your eye health .

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