Cornea - the clear front window of the eye. The cornea transmits and focuses light into the eye.

Iris - the colored part of the eye. The iris helps regulate the amount of light that enters the eye.

Pupil - the dark center in the middle of the iris. The pupil determines how much light is let into the eye. It changes sizes to accommodate for the amount of light that is available.

Lens - the transparent structure inside the eye that focuses light rays onto the retina.

Retina - the nerve layer that lines the back of the eye. The retina senses light and creates impulses that are sent through the optic nerve to the brain.

Macula - a small area in the retina that contains special light-sensitive cells. The macula allows us to see fine details clearly.

Optic Nerve - the nerve that connects the eye to the brain. The optic nerve carries the impulses formed by the retina to the brain, which interprets them as images.

Vitreous - the clear, jelly-like substance that fills the middle of the eye.
 

Eyecare Information

AMBLYOPIA (am-blee-OH-pee-uh): Amblyopia, or ‘lazy eye’ is decreased vision in one or both eyes without detectable anatomic damage in eye or visual pathways.

APHAKIA: The absence of the crystalline lens of the eye, usually after cataract extraction.

ASTIGMATISM: Optical defect (blurry vision) in which refractive power is not uniform in all meridians. Light rays entering the eye are bent, preventing formation of a sharp point focus on the retina.Astigmatism is corrected by eyeglasses or contact lenses.

CATARACT: opacity or clouding of the crystalline lens that may prevent a clear image from forming on the retina. The lens may require surgical removal if visual loss becomes significant, with lost optical power replaced with an intraocular lens. May be congenital or caused by trauma, disease, or age.

CORNEA: The transparent front segment of the eye that covers the iris,pupil and anterior chamber, providing most of the eye’s optical power.

CRYSTALLINE LENS: The natural lens of the eye, located behind the pupil. The original state of the lens is transparent, but the lens becomes cloudy with age.

DIABETIC RETINOPATHY: Diabetic retinopathy is a complication of diabetes that is caused by changes in the blood vessels of the eye.

DRY EYE SYNDROME: Corneal and conjunctival dryness due to deficient tear production,predominantly in menopausal and post-menopausal women. Can cause foreign body sensation and burning eyes.

EMMETROPIA (em-uh-TROP-pee-uh): Refractive condition in which no refractive error is present and distant images are focused sharply on the retina with no need for accommodation or corrective lenses.

EXCIMER LASER: The excimer laser produces an ultraviolet beam of light which is emitted in pulses. Each pulse removes 1/4000 millimeter of tissue fromthe surface of the cornea. It would take about 200 pulses from an eximer laser just to cut a human hair in half. The excimer laser has beenused in industry since 1971 and has been used in ophthalmic surgery since 1983.

EXTRACAPSULAR CATARACT EXTRACTION: A cataract surgical procedure which removes the cataractous lens but leaves the rear lens capsule intact.

FLOATERS:  Particles that float in vitreous and cast shadows on the retina; seen by patients as spots, cobwebs, spiders, etc.

FUNCTIONAL VISUAL DISABILITY: The degree to which a visual error interferes with a person’s ability to perform normal daily activities, such as reading, driving at night, or performing hobbies.

GLAUCOMA: A group of diseases characterized by increases intraocular pressure resulting in damage to the optic nerve and retinal nerve fibers; documented by typical visual defects and increased size of optic cup.Glaucoma is a leading cause of blindness in the U.S. Loss of sight from glaucoma is preventable if you get treatment early enough.

HYPEROPIA: Also known as farsightedness, hyperopia is a refractive error caused by an eyeball that is too short to focus light on the retina.

INTRAOCULAR LENS (IOL): A plastic lens that may be surgically implanted to replace the natural lens of the eye.
There are numerous styles of IOLs, including foldable IOLs and multifocal IOLs.

IRIS: Pigmented tissue that lies behind the cornea that gives colorto the eye (e.g. green eyes) and controls the amount of light entering the eye by varying the size of the black pupillary opening.

LASER ASSISTED IN-SITU KERATOMILEUSIS (LASIK): Laser Assisted In Situ Keratomileusis, or LASIK, combines PRK with elements of ALK.The ophthalmologist uses the automated microkeratome to shave off a thin, hinged layer of the cornea. The surgeon then uses the excimer laser to vaporizea thin layer of the underlying cornea, and the top flap is restored to its place. LASIK is the newest refractive procedure and therefore there is littlehard data on its outcomes.

MACULAR DEGENERATION: Macular degeneration is damage or breakdown of the macula of the eye.

MICRON (MY-kron): A unit of length equal to one-millionth of a meter.

MULTIFOCAL IOLS: An intraocular lens (IOL), that incorporates several different optical powers, to permit focusing at different distances.

MYOPIA: Also known as nearsightedness, myopia is a refractive error caused by an eyeball that is too long to focus light on the retina or a cornea which is too steeply curved.

OPHTHALMOLOGIST: An ophthalmologist is a doctor of medicine who is licensed to practice medicine and surgery and who specializes inall aspects of eye diseases and disorders and vision care. An ophthalmologists education and training include 4 years of college, 4 years of medical school, one year of internship, and 4 years in a hospital-basedeye residency program.

‘NO SHOT, NO STITCH, NO PATCH’ or ‘QUICK VISION’ CATARACT SURGERY:Surgeons have, until recently, always placed one or more injections of anesthetic beside or below the eye prior to starting cataract surgery.This was done to prevent eye discomfort. Newer techniques of cataract removal combined with the use of foldable lens implants now allow surgeonsto work through very small clear corneal incisions. This procedure is called clear cornea cataract surgery (No Shot). With this procedure,the cornea is completely anesthetized (numbed) with topical eyedrops, making injections unnecessary.

PHACOEMULSIFICATION (fay-loh-ee-mul-sih-fih-KAY-shun): A cataract surgical procedure which uses an ultrasonic vibration to shatter and break up acataract, making it easier to remove. The vibration is delivered by an irrigation-aspiration instrument.

POSTERIOR CAPSULAR OPACIFICATION (PCO): Opacification of the posterior lens capsule, sometimes called “secondary cataract”, is often a consequence of modern cataract surgery. It occurs when a thin membrane of tissue grows over the remaining capsule following cataract surgery, and can develop in as many as half of all cases between several months and several years after surgery. PCO is treated using the YAG laser on an outpatient basis.

PHOTOREFRACTIVE KERATECTOMY (PRK): A surgical technique employing an excimer laser to reshape the surface of the cornea and thereby reducing nearsightedness.

PRESBYOPIA: Also called “old age vision”, presbyopia occurs as the lensof the eye ages and becomes less elastic and able to accommodate. Usually becomes significant after age 45 and is often signaled by the need for bifocals.

PTOSIS: Drooping of upper eyelid.

PUPIL: The variable-sized, black circular opening in the center ofthe iris that controls the amount of light that enters the eye.

RADIAL KERATOTOMY (RK): A surgical technique employing radial incisions made in the periphery of the cornea to allow the central cornea to flatten, reducing its optical power and thereby nearsightedness.

RETINA:  The thin lining at the back of the eye that converts images from the eye’s optical system into electronical impulses sent along the optic nerve for transmission to the brain.

SCLERAL INCISION: the external white of the eye through which an incision is made during a cataract operation that uses a scleral incision.

STRABISMUS (struh-BIZ-mus): Eye misalignment caused by extraocular muscle imbalance: one fovea is not directed at same object as the other.

YAG LASER: The YAG laser is a surgical instrument that emits a shortpulsed, high energy light beam that can be precisely focused by computer to cut, vaporize, or fragment tissue. The YAG laser is used to treat posteriorcapsular opacification; a clouding of the remaining capsular tissue that develops postoperatively in as many as half of cataract removal operations.The tissue is vaporized with carefully controlled pulses of the YAG laser, and the surgery is performed on an outpatient basis.