How to Read Your Eyeglass Prescription


How to read your eyeglass prescription? When you look down at your eyeglass prescription, the numbers and the abbreviations staring up at you can be quite confusing.

Many others who also have trouble interpreting their prescription card share your puzzled expression. Can reading your eyeglass prescription be this hard? Once you know what the abbreviations stand for and what the numbers next to them mean, you will be able to decipher your prescription card.

1.    Learn What The Different Abbreviations Stand For

O.D. or oculus dextrus refers to your right eye whereas O.S. or oculus sinister refers to your left eye. Another prescription term you need to familiarize yourself with is OU or oculus uterque, which refers to both eyes.

Some eye doctors have tried to modernize the manner in which they write an eye prescription, substituting the Latin terms for RE meaning right eye and LE meaning left eye. Which information comes first on the prescription card? The prescription card will state the results for your right eye first, and then the left eye.

2.    Determining If You Are Farsighted Or Nearsighted

SPH determines the prescription power of each eye. This number allows the eye doctor to determine if you are farsighted or nearsighted. Negative numbers suggest you are nearsighted and positive numbers suggest you are farsighted.

Next to the number, a “-“and “+” sign will be written. Again, the “plus” sign indicates farsightedness and the “minus” sign indicates nearsightedness. If your sight is extremely poor, the number will be further away from the zero. The numbers represent diopters or the focusing power. Lenses are designed using diopters.

For Example: If the prescription states -1.00, you are nearsighted and have one diopter. If you are -4.25, you are nearsighted and have 1/4 and 4 diopter. The second result states that a person will require thicker lenses. For farsightedness, +1.00 equals a small amount whereas +5 indicates you will require thicker lenses.

3.    Determining If You Have Cylindrical Vision

Does your prescription card have three numbers? If so, the eye doctor will diagnose you with astigmatism. The cylinder may have a minus or a plus sign next to it to indicate the severity of your astigmatism. If you find the letter “X” written on the prescription—a digit that is between 0 and 180—it stands for the astigmatism’s orientation.

For Example: If you have -1.00 plus 1.50 times 180, you are nearsighted, have astigmatism, and on an axis of 180 degrees. If you have +2.50 plus 2.00 times 45, you are farsightedness, have astigmatism, and on an axis of 45 degrees.

4.    Learn To Differentiate Between The Five Types Of Eyeglass Prescription

Your prescription card will also inform you the type of eyeglass perception you require. There are five in total and they are:

Now, reading your eye prescription will be less of a challenge for you. If you want to order eyeglasses online, you will be able to fill out all the sections without any trouble. Additionally we have made it easier than ever before to provide your eyeglass prescription online, just upload, fax, email or text your prescription to us and we will take care of the rest.