Understanding How Refractive Errors Are Measured
Many prospective LASIK patients wonder if their vision is too good for LASIK. But it is also common for candidates to ask if your vision can be too bad for LASIK. It is difficult to classify refractive errors into categories of “too good” or “too bad.” The path to LASIK is so unique for each patient. Determining whether you are a candidate for LASIK involves assessing your medical history, your vision prescription, your detailed eye exam and corneal topography results, and your personal risks and benefits.
However, there are some guidelines set by the U.S. Food and Drug Administration (FDA) regarding vision prescriptions that are approved for treatment by LASIK. While you are likely not used to seeing vision measured in diopters—a unit that designates the strength of a lens—eye doctors use these measurements when determining prescriptions for glasses or contacts. These are the FDA limits for LASIK surgery as outlined by the American Refractive Surgery Council:
- Up to +6.00 diopters of hyperopia (farsightedness)
- Up to 6 diopters of astigmatism
- Up to -12.00 diopters of myopia (nearsightedness)
Before you try to calculate or assume where your vision prescription falls in the limits above, we recommend speaking to your primary eye doctor or scheduling a LASIK consultation. If you would like to improve your quality of life by reducing your dependency on glasses or contacts, it is worth pursuing LASIK to determine whether you are a strong candidate.