LASIK Eye Surgery Glossary: Term Definitions

Acuity

Acuity refers to the sharpness or clarity of your vision.

Cornea

The cornea is the transparent front portion of the eyeball that covers the iris and pupil.

Corneal Epithelium

The corneal epithelium is the thin, protective layer encasing the eyeball. Prior to LASIK eye surgery, the epithelium must be lifted or polished away to expose the underlying cornea. Epithelial cells regenerate quickly, facilitating fast healing.

Diopter

A diopter is one whole number on a prescription. The number of diopters on your prescription represents how much correction is needed to normalize your vision. The more myopic or hyperopic you are, the higher your prescription will be represented in diopters. Myopic, or nearsighted prescriptions are normally indicated by negative numbers, such as -4.75. Hyperopic, or farsighted prescriptions are normally indicated by postitive numbers, such as +4.75.

Excimer Laser

An excimer laser refers to a cool laser. Excimer lasers use cool beams of ultraviolet light to evaporate corneal tissue during vision correction.

Farsightedness

Farsightedness is another name for hyperopia or hyperemetropia. Many farsighted patients have difficulty seeing things up close, but often have crisp-acute distance vision.

Hyperopia or Hyperemetropia

Hyperopia and hyperemetropia are others terms for farsightedness. Many hyperopic patients have difficulty seeing things up close, but often have crisp-acute distance vision.

Iris

The iris is the colored portion of the visible eye. It is a muscle that affects the size of the pupil, depending on the amount of light the eye needs to see in a given environment.

Keratectomy

“Keratos” is the Greek word for cornea, and “ectomy” means to remove. Together they mean to remove corneal tissue.

Keratomileusis

“Keratos” is the Greek word for cornea, and “mileusis” means to reshape. Together they mean to reshape the cornea.

Keratotomy

“Keratos” is the Greek word for cornea, and “otomy” means to create an incision. Together they mean to create an incision in the cornea.

LASIK

LASIK is an acronym that allows us to quickly say, “laser-assisted in situ keratomileusis.” This is more simply said as “reshaping the cornea using a laser.”

Lens

The crystalline lens of the eye is a transparent, biconvex structure that works with the cornea to help refract light to be focused on the retina. The lens, accomodates, or changes shape to allow vision to focus on objects at various distances.

Microkeratome

A microkeratome is a precision surgical instrument with a thin blade designed for creating the corneal flap during a LASIK procedure. Today, premium LASIK providers more frequently use a laser to create the corneal flap.

Monovision

When one eye is deliberately corrected for distance vision and the other for close vision.

Myopia

Myopic patients typically have difficulty seeing objects at a distance. Myopia can be so severe that people also have difficulty seeing objects up close.

Nearsightedness

Nearsightedness is another name for myopia. Nearsighted people typically have difficulty seeing objects at a distance. Nearsightedness can be so severe that people also have difficulty seeing objects up close.

Ophthalmologist

An ophthalmologist is a medical doctor whose specialization is vision. An ophthalmologist can diagnose, treat and manage vision concerns; prescribe medicine and perform surgery (including laser eye surgery.

Optician

An optician makes glasses and performs adjustments on frames.

Optometrist

An optometrist is a doctor whose specialization is vision. An optometrist can diagnose, treat and manage vision concerns.

Photorefractive Keratectomy (PRK)

PRK is a corneal procedure where the superficial cornea is removed to improve vision. PRK is an alternative to LASIK.

Presbyopia

“Presbys” is Greek for “old man” and “opia” refers to the eye. Presbyopia typically occurs in our late thirties or early forties, and it can make reading things up close difficult. Our lenses lose their ability to accommodate, or change shape. Some patients may be good candidates for monovision as treatment for presbyopia.

Pupil

The pupil is the dark opening in the visible eye. It will open when more light is needed to see, and it will get smaller if less light is needed to see.

Refractive Error

This word refers to vision problems associated with the cornea, including astigmatism, hyperopia and myopia.