Definitions (A-Z)

Here are some simple definitions to enhance your understanding of LASIK:

• Acuity - how sharply or clearly you see.


• Cornea - The cornea is the transparent front portion of the eyeball, where contact lenses ‘contact’.


• Diopter - A diopter is a unit of measurement of the optical power of a lens, such as an eye. A child’s eyes start at 15 to 20 diopters and this drops to about 10 diopters at age 25, to around 1 diopter at 50 years and over.


• Excimer Laser - An excimer laser is a cool laser, using beams of ultraviolet light to shape the cornea.


• Farsightedness - Farsightedness or Hyperopia means difficulty seeing things up close, but usually good distance vision.


• Iris - The iris is the colored part of the eye that regulates the size of the pupil.


• Keratectomy – A procedure that removes corneal tissue.


• Keratotomy – A procedure to create an incision in the cornea.


• Keratomileusis – A procedure to reshape the cornea.


• LASIK - "Laser assisted in situ keratomileusis." or "reshaping the cornea using a laser."


• Lens - The lens of the eye is behind the iris and focuses light rays to form an image on the retina.


• Microkeratome - A vibrating hand-held blade used to create a flap in the cornea during LASIK Surgery.


• Monovision - When one eye is corrected for distance vision and the other for close vision.


• Myopia - Myopic people typically have difficulty seeing objects at a distance. Myopia can be so severe that people have difficulty seeing objects up close too.


• Nearsightedness - Nearsightedness is another name for Myopia. Nearsighted people typically have difficulty seeing objects at a distance. Nearsightedness can be so severe that people have difficulty seeing objects up close too.


• Ophthalmologist - An ophthalmologist is a medically trained surgical specialist whose specialization is vision. An ophthalmologist can diagnose vision concerns, treat vision conditions, manage vision conditions, perform eye surgery, prescribe medicine, and ophthalmologists can perform laser eye surgery.


• Optician - An optician makes glasses and does adjustments to frames.


• Optometrist - An optometrist is a doctor who can diagnose, and treat vision conditions and prescribe treatment.


• PRK or Photorefractive Keratectomy - PRK is a refractive laser procedure where no corneal flap is created. PRK results can be as good as LASIK but healing and recovery times are considerably longer.


• Presbyopia - Presbyopia is loss of acuity due to ageing and begins in the late thirties or early forties. A LASIK procedures called Monovision is sometimes recommended for presbyopia.


• Pupil - The pupil is the dark opening in the eye, opening or dilating when more light is needed to see, contracting or closing when less light is needed.


• Refractive Error - This word refers to type and degree of vision problems associated with the cornea: Astigmatism, Hyperopia, and Myopia.