Before you receive contacts, Dr. Kalfayan at Atlantic Eye Care & Spa will conduct an exam to determine the prescription of your contacts. You'll find all the information you need to know about your prescription is on one side of your contact boxes. For instance, the prescription will include the power of your lenses -- a number that could range between 20.00 and -20.00, but some contact brands don't offer that range of powers. Your prescription may also have other readings as well, such as spherical (SPH) and cylindrical (CYL).
You may notice that your prescription says "SPH" and has a number beside it with a plus or a minus before it. Spherical and power can be used interchangeably. They're both ways of expressing the lens power you require to correct your nearsightedness or farsightedness. This measurement is in diopters.
If you have a plus sign in front of the number, you're farsighted, meaning objects far away appear clear but objects close up are blurry. On the other hand, a minus sign in front of the number means you're nearsighted or can't see far away but can see up close.
A larger number means that you have a greater deficit while smaller numbers mean you have less of a deficit.
Not all eye prescriptions will have a number listed after cylindrical. You'll only have a number after the "CYL" if you have astigmatism -- a condition that causes your eyesight to appear blurry as a result of an irregularly shaped eye. A person with astigmatism will have an eye that's more shaped like a football than a ball. Additionally, you may not see a number here if you have mild astigmatism that doesn't require correction.
You'll notice a plus or a minus sign in front of this number, which represents where you have nearsighted or farsighted astigmatism. You'll have a plus for farsighted astigmatism and a minus for nearsighted astigmatism.
The number after the cylindrical reading represents the meridian of astigmatism. A bigger number means a more significant degree of astigmatism, which requires greater vision correction.
These are just two values on your prescription label. Dr. Kalfayan determines all these values through an eye exam that includes a visual acuity test as well as a contact lens fitting. If you have any questions about these or any other value listed on your prescription or need to book an appointment for an eye exam, contact our office at (954) 946-3939.