Regular eye exams are an important part of keeping your eyes looking healthy and sharp.
During your eye exam, an ophthalmologist, optometrist, or ophthalmologist will check for signs of eye disease. If your vision needs correction, you will be given a prescription for glasses or contact lenses.
However, eye prescriptions can be difficult to decipher. They usually contain a series of numbers and letters that can be confusing if you don’t know what they mean.
This article will help you understand the abbreviations and numbers that may appear in your eye prescription. It also explains how prescriptions can vary depending on the vision problem.
Your eyeglass or contact lens prescription will contain various abbreviations, many of which will be followed by numbers.
Here is a summary of what these acronyms mean:
Many of the abbreviations on your prescription are followed by numbers.
If the numbers are marked with a plus sign (+) or no sign, you are farsighted. If the numbers are marked with a minus sign (-), you are myopic.
Some of the numbers in your prescription tell the eyewear manufacturer how much correction your vision needs. Eyeglass power is measured in dioptres.
If your prescription is -1.00, it means your glasses need a power of 1 diopter to correct myopia.
If your prescription is +2.50, your glasses need a power of 2.5 diopters to correct farsightedness. The higher the number, the more correction your vision needs.
Nearsightedness, or nearsightedness, is a common refractive disorder. If you’re nearsighted, you can see objects that are close by clearly, but objects that are farther away appear blurry.
With myopia, your eye is usually elongated, with too much space between the cornea at the front of your eye and the retina at the back of your eye. Myopia can also occur when the cornea of your eye is curved too much.
Because of this greater distance, light rays fall in front of your retina (a light-sensitive structure that sends signals to your brain) rather than on it. This can cause your distance vision to be blurry.
The lenses in your glasses will
In the case of short-sightedness, the strength of the lenses is marked with a minus sign. The more myopic you are, the higher the numbers will be.
For example, a lens power of -5.00 is a stronger power than -2.00. The strength of the lenses can vary for each eye.
Farsightedness, or hyperopia, is a refractive disorder that makes close objects harder to see than distant objects. This happens because the distance from the cornea to the retina is too short, or because your eye’s cornea isn’t curved enough.
If you are farsighted, light is focused behind your retina rather than directly on it.
In the case of long-sightedness, the strength of the lenses is marked with a plus sign. The more far-sighted you are, the higher the numbers will be. For example, a lens power of +4.50 is stronger than a power of +2.00.
Correcting your vision with glasses or contact lenses, for both nearsightedness and farsightedness, can also help prevent:
- burning or stinging in the eyes
Astigmatism is an irregular curvature of either the lens or the cornea of your eye. This irregular curve can bend the light entering your eye and affect the way it hits your retina. Astigmatism can blur both near and distant objects. It can also distort the images you see.
Astigmatism is not uncommon. In fact, the American Academy of Ophthalmology reports that 1 in 3 people suffer from this condition.
If your astigmatism measures 1.5 diopters or more, you may need to wear glasses or contact lenses to see properly. However, if you suffer from astigmatism, you will appreciate the added clarity of wearing prescription glasses.
Your prescription will indicate how severe your astigmatism is and where the irregular curvature appears on your eye.
Your eyeglass prescription may also include notes from your optician or optometrist about other characteristics of your glasses or contact lenses. Your lenses could:
- be progressive or bifocal, meaning they correct both distance and near vision.
- have an anti-reflective or anti-glare coating to reduce glare so you can see better at night or when working on a computer
- Be photochromic, meaning they will darken or lighten depending on the light levels around you
- treated with a coating to make them more scratch-resistant
Yes. Since contact lenses sit directly on the surface of the eye, they must have the same curves as your eye.
A contact lens prescription includes measurements for:
- base curve: a number, usually between 8 and 10, that corresponds 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 will also identify the brand and lens type and an expiration date. Contact prescriptions need to be updated from year to year to reflect changes in your vision and to ensure they are a correct fit.
The American Optometric Association recommends that you have an eye exam at least every 2 years if you are under the age of 60 and every year if you are over the age of 60.
It’s important to have your vision and eye health checked regularly because some serious eye conditions, such as B. glaucoma, have no recognizable early symptoms.
An optometrist can test your eyes and spot changes early, which can prevent vision loss. The tests are quick and painless and can also help detect the following eye conditions:
Eye exams can also show if another medical condition, such as diabetes or high blood pressure, could be affecting the health of your eyes.
The abbreviations and numbers on your eyeglass prescription tell the eyeglass manufacturer what type of lenses you need and how strong they need to be. This information also shows the degree of nearsightedness, farsightedness or astigmatism in each of your eyes.
Because contact lenses sit directly on the surface of your eye, they require additional information, such as: B. the fundus and the bulge of your eye.
Your glasses or contact lens prescription is not a one-time situation. Over time, your vision can change, so it’s important to see an eye doctor at least every few years to protect your eye health.