LASIK Glossary of Terms

There many medical terms and jargon you might come across when reading about laser eye surgery. How can you keep track, and what do they all mean? Consider the following common LASIK terms.


Ablation zone

In the medical field, ablation zone refers to the area of tissue that is removed during laser eye surgery.


The sharpness or keenness of vision. The better one’s vision, the higher one’s level of visual acuity is.


A distortion of the image on the retina caused by an irregular shape to the eye. An astigmatic cornea negatively affects both near and distance vision by projecting light in two different places in the eye.


Bilateral LASIK

The term used to indicate LASIK surgery is being performed on both eyes.



The font part of the eye which refracts lights onto the retina at the back of the eye. This cornea is the part of the eye that is reshaped during laser eye surgery.

Custom LASIK or Custom Wavefront Optimized LASIK

See “Wavefront LASIK surgery”.



A unit of measurement used in determining the refractive error for vision correction.


Excimer Laser

A laser used during LASIK which uses ultraviolet light to reshape the cornea.


FDA (Food and Drug Administration)

The U.S. governmental agency which evaluates and approves medical devices.

Flexible Spending Account (FSA)

An employer-sponsored benefit that allows you to pay for eligible medical expenses, such as LASIK, on a pre-tax basis. A Flexible Spending Account may also be referred to as flex plan, reimbursement account, Tax Saving Plan, Medical Spending Account, or a Cafeteria Plan.


Health Savings Account (HSA)

A savings account that is used in conjunction with a high-deductible health insurance plan that allows you to save money, tax-free, for medical expenses.

Hyperopia (Farsightedness)

A refractive error in the cornea which results in the inability to see near objects as clearly as far objects.


LASIK (Laser-In-Situ Keratomileusis)

A type of vision correction surgery where an eye doctor surgically creates a flap in the patient’s cornea, and an excimer laser is used to gently reshape the cornea.

Lower-Order Aberrations

These are refractive errors which include myopia, hyperopia and astigmatism. These are commonly corrected by LASIK surgery.


Myopia (nearsightedness)

The inability to see distant objects as clearly as near objects.



The inability to focus on objects up close. This condition is due to the loss of elasticity of the lens of the eye, typically occurring in middle age.

PRK Laser Eye Surgery (Photo Refractive Keratectomy)

A type of refractive surgery in which an excimer laser, programmed with the patient’s exact prescription, is used to polish and reshape the curve of the cornea.


Wavefront LASIK surger

A type of laser eye surgery where a specialized technology creates a 3-D map of the eye’s visual system. This map analyzes unique imperfections in the patient’s vision. This allows for extremely precise, individualized vision correction.