Find A TLC Center

Enter your zip code to find centers near you.

Common LASIK Terms


The capacity of the eye to see fine detail.

Affiliated TLC Doctors

Eye doctors who are part of TLC's large network of affiliated optometrist and are trained to manage patients before and after laser vision correction. These doctors collaborate with the surgeons at TLC Laser Eye Centers to determine your candidacy for LASIK. Nearly one out of every four practicing optometrists in North America have affiliated themselves with TLC.


A drug that provides a loss of feeling or numbness in a certain area of the body.

Anesthetic Drops

Numbing drops that are placed on the eye prior to LASIK to help minimize any discomfort during the procedure.


A term used to describe an eye that is not perfectly round. An astigmatic eye is one that has a more complex shape (think about the difference in shape between a ping pong ball and an egg). Astigmatic corneas focus light in two different places in the eye, making both near and distance vision difficult. Our TLC LASIK blog can answer more of your questions about astigmatism and LASIK.

Best corrected visual acuity (BCVA)

The best possible vision a person can achieve with corrective lenses, as measured in terms of Snellen lines on an eye chart.

Bilateral LASIK

LASIK surgery that is performed on both eyes.

Bladeless LASIK

A type of LASIK in which the surgeon uses the IntraLase laser to create the protective corneal flap. In both the LASIK and Custom LASIK procedures, a flap of corneal tissue is created and then folded back. The bladeless LASIK technology allows surgeons to safely create a uniform corneal flap for every patient, without the use of any blades.


The term used to describe the natural crystalline lens once it has become cloudy. Clouding of the lens is typically a result of the aging process, but can be caused by trauma, infection or inflammation.

Cataract Surgery

Removal of the natural lens that has become clouded with age and replacing it with an intraocular lens implant. To discover more about cataract surgery, visit our TLC LASIK blog.


The transparent portion of the eyeball that aids in focusing light onto the retina at the back of the eye. This is the part of the eye that is reshaped with laser vision correction surgery such as LASIK. The cornea is composed of five layers of tissue.

Corneal Epithelium

Soft surface tissue that covers the front of the cornea.

Cornea Flap

The first step in the LASIK procedure involves creating and manipulating a protective flap on the cornea.

Custom LASIK

A procedure that allows your surgeon to customize the LASIK procedure to your individual eyes. Custom LASIK uses an instrument called a wavefront analyzer to measure the way light travels through your eye. The wavefront analyzer creates a detailed map of your eye's unique visual properties. This data is then used to program the excimer laser to customize your treatment.


A unit of measurement used to describe the light bending properties of an optical system. Glasses that correct for nearsightedness are expressed as negative (-) numbers and positive (+) for farsightedness.

Dry Eyes

A deficiency in the production of tears. The main notable symptom is the feeling of sandpaper in the eye (foreign body feeling).

Excimer Laser

A laser using cool beams of ultraviolet light, used to perform LASIK procedures.

Farsightedness (Hyperopia)

A refractive error in which you see better from a distance than close up. Hyperopia is caused by an eyeball that is too short to focus light on the retina.

Flexible Spending Account (FSA)

An FSA account is an employer-provided health savings account (available in the United States only). it allows employees specific tax advantages when setting aside funds for qualified medical procedures. LASIK is a qualified FSA expenditure.

Health Savings Account (HSA)

Not to be confused with an FSA, and HSA is an account created for people who are currently covered under a high deductible health plan. This account allows individuals to save for medical expenses that HDHP's do not cover. The contributions made into this account are made by the individual and/or their employer and are limited to a certain yearly amount. For more information please visit the TLC LASIK blog.

Higher-Order Aberrations

Irregularities, other than refractive errors, that can cause such problems as decreased contrast sensitivity or night vision, glare and halos. Higher-order aberrations do not always affect vision.

Health Reimbursement Account (HRA)

This type of account is an employer-funded plan that will reimburse employees for out-of-pocket medical expenses that are not covered by the company's standard insurance plan. Reimbursement dollars received by the employee are generally tax free. For more information please visit the TLC LASIK blog.


Within the eye.

Intraocular Lens

A lens implanted within the eye to replace the existing crystalline lens. This lens helps to refract light which is focused on the retina.

IOL (Intraocular Lens Implant)

Implanted lens used to replace the crystalline lens of the eye due to cataract clouding or as a form of refractive vision correction. For more information on IOL please visit the TLC LASIK blog.


Is the thin, circular portion of you eye that creates the color (green, brown, blue). It controls the size of your pupil allowing certain amounts of light to reach the retina to focus.


To remove the corneal tissue, this is done to complete the LASIK procedure.


LASIK (Laser-In-Situ Keratomileusis) is currently one of the most frequently performed elective procedures in North America. It is a highly effective outpatient procedure that is suitable for low, moderate and higher prescriptions. In LASIK, a protective hinged flap is created and gently lifted by the surgeon. Then, a computercontrolled cool beam of light from the excimer laser is used to gently reshape the front surface (cornea) of your eye.

LASIK Candidate

A LASIK candidate is a patient who meets a series of criteria that make them an ideal candidate for the LASIK procedure.

LASIK Consultation

A LASIK consultation is used to determine whether a person is a good candidate for LASIK laser vision correction. During a LASIK consultation, the patient meets with their doctor to have a comprehensive eye exam, and discuss different LASIK correction options available, as well as which LASIK procedure will yield the best post-op vision results based on their prescription.

LASEK (laser epithelial keratomileusis)

LASEK also know as "Epi-LASEK" is similar to traditional LASIK but differs in how the corneal flap is created. In LASEK the flap is created by using an alcohol based solution to lift the cornea instead of using a surgical intrument called a microkeratome (which is used to surgically create the flap in traditional LASIK). This procedure is often used when patients have thin corneas that are not suitable for tradition LASIK. For more information please visit the TLC LASIK blog.


The lens is the clear structure located behind the pupil. Its primary function is to provide fine-tuning for focusing and reading, which it accomplishes by altering its shape.

Lid Speculum

An instrument, placed in the eye before surgery, to gently hold the lids apart, eliminating possibility of blinking.

Lower-Order Aberrations

Also called refractive errors; includes myopia, hyperopia and astigmatism.


The blade which is used to make the corneal flaps during the beginning stages of a LASIK procedure.

Monofocal Lens

An intraocular lens implant which allows clear vision at one specific distance.


When, with vision correction, one eye is intentionally left slightly nearsighted. This allows you to maintain your ability to read after presbyopia begins. Gaining this near vision means giving up some distance sharpness.

Multifocal Lens

An intraocular lens implant, similar to a bifocal or trifocal lens, which allows vision at many different distances.

Nearsightedness (Myopia)

A refractive error in which you see better close up than from a distance. Myopia is caused by an eyeball that is too long to focus light on the retina or a cornea which is too steeply curved.

Night Glare (Halos)

Night glare occurs when a person is seeing a halo type shape around lights at nighttime. They can be bright or dull, and can be a potential negative side effect of laser vision correction.

Off-label Use

In the United States, the regulations of the Food and Drug Administration (FDA) permit physicians to prescribe approved medications for other than their intended indications. This practice is known as off-label use.


The anatomy, physiology and study of eye diseases. These are considered both surgical and medical professionals.


Makes vision correction lenses and performs necessary adjustments,


The visual system and information processing profession. Able to diagnose certain diseases and help regulate sight by lens prescription. Considered a medical and non surgical professional.


A potential side effect of laser vision correction, over-correction happens when the healing of the eye is over anticipated. Your eyes can heal better or less than the surgeon expected, thereby determining whether the final prescription is more or less than what the surgeon had originally intended for correction.


Presbyopia develops as the lens of the eye loses some of the flexibility that characterizes a younger eye. Everyone experiences the effects of presbyopia, typically between the ages of 40 and 50. For more information on presbyopia please visit the TLC LASIK blog.


Describes the healing period after your LASIK procedure, and comes with certain requirements for a healthy and successful LASIK recovery.

PRK (Photorefractive Keratectomy)

Prior to LASIK, PRK was the most common laser vision correction procedure. For the PRK procedure, the surgeon first removes the eye's protective first layer of cells, or epithelium, to reveal the next layer of corneal tissue. The surgeon will apply computer-controlled pulses of cool light from the excimer laser to reshape the curvature of the eye. PRK patients require about three days for the epithelium to heal and allow clearer vision. For more information on PRK please visit the TLC LASIK blog.


The pupil is the "black circle" in your eye. The primary function of the pupil is to control the amount of light entering your eye. When you are in a bright environment, the pupil becomes smaller to allow less light to pass through. When it is dark, the pupil expands to allow more light to reach the back of your eye.


The retina consists of fine nerve tissue that lines the inside wall of the eye and acts like the film in a camera. Its primary function is to capture and transmit images.

TLC Advantage Program

We at TLC strive to make LASIK affordable for every patient by offering special savings. TLC partners with many of the major vision and health care companies offering employee benefit programs. TLC also partners with individual employer groups. TLC's partners receive a special savings when their members have laser vision correction performed at a TLC Advantage Program Network location.

Toric Lens

An intraocular lens implant which is design to correct astigmatism.

Uncorrected visual acuity (UCVA)

The best possible vision a person can achieve without corrective lenses measured in terms of Snellen lines on an eye chart.

Visual Acuity

Acuteness or clearness of vision. For more information on visual acuity please visit the TLC LASIK blog.

Wavefront Analyzer

Originally developed for use in high-powered telescopes to reduce distortions in space, now adapted for eyecare. A single beam of infrared laser light is passed into the eye and focused on the retina. The light is then reflected off the retina, passed back through the eye, through a lenslet array to a sensor, and then analyzed from 200 different aspects to create a map of the eye - or fingerprint of vision. This technology uncovers unique characteristics of the eye never measured before using standard methods for glasses and contact lenses.