Glossary

Patients who play an active role in their own health care sometimes need a clear understanding of medical terminology used by their doctors. This on-line glossary helps patients become familiar with terms and definitions that may be part of their care and treatment at Wheaton Eye Clinic.

a
Adie Pupilsearch for term

A pupil condition in which the pupil is initially enlarged and the eye has difficulty focusing on close objects, such as a book. The pupil eventually becomes small and non-reactive.

Amblyopiasearch for term

Sometimes referred to as “lazy eye”, this term refers to poor vision in an eye that did not develop normal sight during childhood.

Anisocoriasearch for term

An eye condition in which the pupils in the right eye and the left eye are not the same size. A small difference in pupil size is normal however, more than a small difference, or other finding such as ptosis, may indicate a neurologic problem.

Anisometropiasearch for term

This eye condition occurs when one eye has significantly different refractive error than the other, and the more disadvantaged eye (e.g. the more far-sighted one) may not develop normal vision.

Anterior Ischemic Optic Neuropathy (AION)search for term

This is the most common cause of sudden decreased vision in patients older than 50 years. It involves a sudden blurriness, dimness or darkness, often above or below where a person is looking. Usually there is no discomfort, redness or tearing.

Anterior Stromal Puncturesearch for term

An in-office treatment for corneal erosion in which the physician makes small punctures into the area in order to create a scar to hold new cells in place.

Aphakiasearch for term

A condition in which the lens of the eye is absent, usually due to surgical removal in the treatment of cataracts.

Artificial Tearssearch for term

Eyedrops, available without prescription, used to lubricate the eye and help maintain moisture.

Astigmatic Keratotomy (AK)search for term

A surgical procedure used to treat astigmatism.

Astigmatismsearch for term

A common corneal irregularity in which the cornea has an uneven curvature, with both steeper and flatter curves, which causes distorted near and far vision.

b
Basal Cell Carcinomasearch for term

A common type of eyelid skin cancer that has various appearances but typically grows at a relatively slow rate.

Benign Essential Blepharospasm (BEB)search for term

A condition in which uncontrolled blinking, squeezing and eyelid closure occur in both eyes without stimulation or other apparent cause.

Biopsysearch for term

A procedure in which a lesion is removed and sent to a pathologist, a physician trained at evaluating microscopic tissue for signs of disease.

Blapharospasmsearch for term

This is a condition that describes the involuntary clenching of eyelid muscles.

Blepharoplastysearch for term

A surgical procedure that removes excess skin. This can be either a medical or cosmetic procedure.

Botulinum Toxin (BOTOX)search for term

A medicine which relaxes and weakens facial muscles in order to prevent spasms.

c
Cataractsearch for term

Cloudiness or opacity in the eye’s natural lens.

Cellophane Maculopathysearch for term

(See Macular Pucker)

Choroiditissearch for term

Inflammation of the choroids.

Conjunctivitissearch for term

Commonly called “pink eye”, this is an inflammation of the clear skin that covers the white part of the eye and the inside surface of the eyelids. This is most commonly caused by infection (either viral or bacterial) or allergy.

Corneal Basement Membrane Dystrophysearch for term

The most common dystrophy of the cornea in which the surface of the cornea has numerous fingerprint lines, dots, or whitish cysts which give blurred or ghost-like vision.

Corneal Dystrophiessearch for term

An inherited condition which usually develops in both eyes and affects the surface of the cornea, the middle layers or the deepest parts. There are many types of dystrophies. They usually are slowly progressive and may or may not decrease vision.

Corneal Ulcerssearch for term

Infections of the cornea caused by bacteria, viruses, fungi or parasites.

CT Scansearch for term

Computerized Tomography (CT) combines a series of x-ray views taken from many different angles to produce cross-sectional images of the bones and soft tissues inside the body.

Custom Cataract Surgerysearch for term

Cataract surgery during which additional procedures, such as implanting an accommodating or toric intraocular lens to produce clearer vision after cataract surgery, reduces the dependence on glasses or bifocals.

Custom Vue LASIKsearch for term

Laser vision correction using the WaveScan system which allows surgeons to measure and correct visual imperfections that were previously undetectable with the common technology used to prescribe glasses and contact lenses.

d
Dacryocystorhinostomy (DCR)search for term

A surgical procedure that creates a bypass away from a blocked tear duct.

Dermatochalasissearch for term

The medical term for excess skin of the eyelids.

Dilationsearch for term

A part of the eye examination in which eye drops are used to make the pupil larger in order to allow the doctor to examine the optic nerve and back part of the eye. This is painless and results in blurry vision for several hours following the examination.

Dry Eyesearch for term

This common condition is characterized by low tear production or poor tear quality due to improper balance of the three layers of tear film: mucus, aqueous and lipids.

e
Ectropionsearch for term

In this condition the lower eyelid pulls away from the eye resulting in tearing and eye irritation.

Enhancement Tint Contact Lensessearch for term

Contact lenses which have a mild tint throughout the lens and are designed to enhance the color of the eye.

Entropionsearch for term

This a common condition, particularly in the mature population, in which the lower eyelid rotates inward toward the eye due to weakening of lower eyelid muscles.

Epiblepharonsearch for term

This is an eyelid condition that describes the inward direction of skin and eyelashes that is commonly found in young individuals of Hispanic and Asian descent.

Epiretinal Membranesearch for term

(See Macular Pucker)

Epithelial Debridementsearch for term

Loose cells are removed from a recurrent corneal erosion and a bandage soft lens is applied until the cells are healed.

Epitheliumsearch for term

The clear, outer membrane layer of the cornea and conjunctiva.

Excimer Laser Phototherapeutic Keratectomysearch for term

See PTK (Excimer Laser Phototherapeutic Keratectomy)

Eye Emergencysearch for term

Any eye condition that is perceived by the patient as needing immediate attention, This includes sudden loss or distortion of vision, ocular trauma (such as blunt force trauma, puncture, chemical splash into eye, foreign bodies in the eye) double vision or sudden pounding headache.

f
Flasherssearch for term

Flashing lights,or lightening streaks in the field of vision caused when the vitreous gel inside the eye rubs or pulls on the retina.

Floaterssearch for term

Tiny clumps of vitreous gel or cells inside the eye that appear as small specks or clouds moving in the field of vision. This often occurs when looking at a plain background such as a blank wall or blue sky.

Fuchs Corneal Dystrophysearch for term

A corneal dystrophy most common in females after 50 years of age.

g
Gas Permeable Contact Lensessearch for term

Contact lenses made of plastics which “breath” oxygen to the eye, providing better safety and comfort.

Glaucomasearch for term

A progressive condition in which the major nerve of the eye, the optic nerve, is damaged due to increased internal eye pressure.

Glaucoma Implantsearch for term

This small device enhances standard glaucoma surgery by increasing outflow of fluid and decreasing intraocular pressure. The implant is designed to allow aqueous fluid to flow out of the eye by way of the implant.

Gonioscopysearch for term

A part of the eye examination in which the doctor inspects the eye’s drainage angle.

Granular Dystrophysearch for term

This inherited dystrophy causes “granular” looking spots in the cornea which decrease vision.

Graves’ Thyroid Eye Diseasesearch for term

A condition resulting from excessive function of the thyroid gland (hyperthyroidism).

h
Hemifacial Spasmsearch for term

This is a chronic condition in which patients experience involuntary spasms on one side of the face. The affected side of the face seems to “scrunch up” while the other side remains normal.

Horner Syndromesearch for term

An eye condition in which the nerve which normally makes the pupil larger is not working properly so that the pupil on that side is abnormally small and the upper eyelid droops.

Hybrid Contact Lensessearch for term

A specialized type of contact lens that is a combination of soft and gas permeable materials. This type of contact lens is reserved for specific eye conditions such as keratoconus, irregular astigmatism, various eye diseases, eye trauma and post surgery.

Hyperopiasearch for term

A vision condition, commonly called farsightedness, in which people have difficulty seeing objects that are close to them.

i
Intraocular Lenssearch for term

A clear man-made lens that replaces the eye’s natural lens to produce clearer vision after cataract surgery.

IOLsearch for term

An abbreviation for Intraocular Lens, a clear man-made lens that replaces the eye’s natural lens to produce clearer vision.

Irissearch for term

The colored part of the eye which is situated between the cornea and the lens and perforated by the pupil.

j
Juvenile Rheumatoid Arthritissearch for term

A childhood disease that causes inflamed, swollen joints and possibly inflammatory eye disease.

k
Keratoconussearch for term

A progressive eye disease in which the clear, dome-shaped surface of the eye (the cornea) thins, gradually producing a cone-shaped bulge in the front of the eye, causing blurred vision and increased sensitivity to light and glare.

l
LASEKsearch for term

A surgical procedure, similar to LASIK, in which there is no cutting. Instead, a solution is applied to the exterior of the eye which allows the doctor to move the epithelium (outer layer) of the eye, perform the laser correction, and slide the epithelium back into place.

LASIKsearch for term

A brief outpatient surgical procedure which uses the science of the laser and the skills of the surgeon to correct nearsightedness, farsightedness and astigmatism.

LASIK & Refractive Surgerysearch for term
Lattice Dystrophysearch for term

In this inherited condition, glass-like branching lines accumulate to decrease vision.

Lazy Eyesearch for term

See ptosis.

Lesionsearch for term

A bump, often on the eyelid, that demonstrates growth, bleeding or crusting.

Limbal Relaxing Incisions (LRI)search for term

A surgical procedure to treat astigmatism.

Lower Blepharoplastysearch for term

A surgical procedure in which excess skin and puffiness of the lower eyelids are eliminated.

m
Maculasearch for term

The center portion of the retina which enables a person to see straight ahead.

Macular Dystrophysearch for term

This is the least common of the middle layer dystrophies and causes large white spots that can grow together causing the whole cornea to become hazier.

Macular Edemasearch for term

Swelling in the macula that reduces central vision.

Macular Holesearch for term

A discontinuity or break in the center portion of the retina, called the macula.

Macular Puckersearch for term

A layer of scar tissue that develops on the macula and distorts the surface, producing blurry or wavy central vision.

Microvascular Cranial Nerve Palsysearch for term

An eye condition in which the affected eye may not be able to move at all in one or more directions. If the eyes aren’t moving together, the patient experiences blurred or double vision.

Migrainesearch for term

Classic migraine attacks start with visual symptoms, such as zigzag colored lights or flashes of light expanding to one side over 10-30 minutes, followed by a pounding severe headache sometimes associated with nausea, vomiting and light-sensitivity.

Monovision Contact Lensessearch for term

A contact lens option that provides both near and distance vision. The patient wears a lens in one eye to correct for distance vision and another lens in the other eye to correct for near vision.

MRIsearch for term

Magnetic Resonance Imaging (MRI) is a medical imaging technology used to visualize detailed internal structures and limited function of the body. MRI provides greater contrast between the different soft tissues of the body, making it especially useful in neurological imaging.

Myopiasearch for term

A vision condition, commonly called nearsightedness, in which objects in the distance are blurry and objects nearby are seen clearly.

n
Nasolacrimal Tear Ductsearch for term

This duct drains tears from the surface of the eye down into the nose.

Nerve Fiber Analysissearch for term

A part of the eye examination in which the thickness of the optic nerve fibers is evaluated.

Neuro-Ophthalmologysearch for term

The subspecialty of ophthalmology which focuses on disorders involving the eye and the brain. Visual problems in this area do not come from the eyes themselves but from disorders involving the nervous system.

Non-Basal Cell Carcinomassearch for term

This term refers to eyelid tumors, such as melanoma, sebaceous cell carcinoma and squamous cell carcinoma, which occur less frequently than basal cell carcinoma, but have a greater ability to metastasize and spread. Due to the aggressiveness of these tumors, it is important to seek medical attention for eyelid “bumps” or lesions.

o
Occlusionsearch for term

This refers to any physical barrier (cataract, droopy eyelid or corneal clouding) that does not permit light to be focused within the eye in a normal fashion, leading to amblyopia.

Opaque Contact Lensessearch for term

These lenses change the color of the eye completely and have a clear center so the patient can see through the lens.

Ophthalmologistssearch for term

Ophthalmologists are medical doctors (M.D.) or doctors of osteopathic medicine (D.O.) who have completed four years of college, four years of medical school, one year of internship, three or four years of an ophthalmology residency and perhaps have further training in a subspecialty fellowship.

Ophthalmoscopysearch for term

A part of the eye examination in which the doctor inspects the retina and optic nerve.

Optic Nervesearch for term

The major nerve of the eye which is responsible for taking light from the retina and sending impulses to the brain which are perceived as vision. Damage to the optic nerve dramatically diminishes eyesight.

Optic Neuritissearch for term

The most common cause of sudden visual loss in patients between the ages of 15 and 45 accompanied by discomfort in or around the eye, particularly with eye movement.

Opticianssearch for term

These health care providers fill prescriptions ordered by ophthalmologists or optometrists by fitting and dispensing lenses for the correction of vision.

Optometristssearch for term

Doctors of optometry (O.D.) have completed four years of college and four years of post-graduate study at a college of optometry. They are licensed to practice optometry and not medicine.

Orbitsearch for term

Bony cavity surrounding the eye.

Orbital Plastic & Reconstructive Surgerysearch for term

A highly specialized practice of ophthalmology and plastic surgery that manages and treats deformities and abnormalities of the eyelids, lacrimal (tear) system, the orbit (bony cavity surrounding the eye) and the adjacent facial structures.

Orthoptic Therapysearch for term

This is a program of eye exercises designed to help people with eye-focusing problems such as a strabismus.

p
Pachymetrysearch for term

A part of the eye examination in which the corneal thickness is measured.

Pediatric Cataractssearch for term

Very rare condition in which a child has a cataract, causing more serious problems than in adults.

Pediatric Glaucomasearch for term

A condition in which the eye pressure is too high and structures inside the eye, such as the optic nerve, can be permanently damaged.

Pediatric Ophthalmologistsearch for term

An ophthalmologist who provides medical and surgical eye care for children under the age of 18.

Pediatric Ophthalmologysearch for term

Medical and surgical eye care for children under the age of 18.

Piggyback Contact Lensessearch for term

A rare design that is a combination of a soft contact lens with a gas permeable lens resting on the top. This is reserved for complex eye conditions that prevent the wearing of normal contact lenses.

Pingueculasearch for term

A benign whitish or yellowish spot or bump on the conjunctiva in the inner or outer corners of the eye which can become larger over time.

Pink Eyesearch for term

See conjunctivitis.

Pneumatic Retinopexysearch for term

A treatment for retinal detachment which uses a gas bubble to push the retina onto the back of the eye.

Pre-Macular Fibrosissearch for term

(See Macular Pucker)

Presbyopiasearch for term

An age-related condition in which the lens of the eye, because it is loosing its flexibility, has difficulty changing focus to see objects that are near.

Prosthetic Eyesearch for term

An artificial eye worn by someone who has lost an eye from injury or other cause.

Pseudotumor Cerebrisearch for term

High pressure inside the head causes problems with vision loss and steady or pounding headache, frequently at the back of the neck. The pain may worsen with bending or stooping; patients also may be aware of a rushing noise in their ears.

Pterygiumsearch for term

A wing-shaped fibrovascular growth that can extend onto the cornea from the inner or outer corner of the eye.

PTK (Excimer Laser Phototherapeutic Keratectomy)search for term

A laser is used to polish the surface of the cornea with the expectation that stronger cells, with stronger adhesion to the eye, are made.

Ptosissearch for term

This refers to the drooping of the upper eyelid(s), a common condition that may cause a reduction in the field of vision.

Punctal Plugssearch for term

A treatment option to conserve a patient’s own tears, this tiny plug helps eyes keep tears longer by blocking the eye’s natural drainage system into the nose.

Pupilometrysearch for term

A part of the eye examination in which pupil size is measured under a variety of different lighting.

r
Recurrent Corneal Erosionssearch for term

A condition seen in eyes that have suffered a sharp abrading injury (paper cuts, tree branch injuries, fingernails) or in patients with pre-existing corneal basement membrane dystrophy.

Refractionsearch for term

A part of the eye examination which checks whether vision can be improved with a new pair of glasses.

Restylanesearch for term

This is an injectable dermal filler, made of hyaluronic acid, which restores skin volume in order to correct moderate to severe facial wrinkles and folds.

Retinasearch for term

The light sensitive tissue lining the back of the eye which converts light rays into electrical impulses that travel through the optic nerve to the brain where they are interpreted as images.

Retinal Detachmentsearch for term

This is a separation of the retina, the light sensitive layer in the back of the eye, from the eye wall. A retinal detachment is an eye emergency and can lead to blindness if not corrected.

s
Scleral Bucklesearch for term

A treatment for retinal detachment which involves wrapping a plastic band around the eye to indent the eye wall to reattach the retina.

Scleral/Semi-Scleral Contact Lensessearch for term

These contact lenses are large diameter gas permeable lenses that rest on the white sclera of the eye and vault the cornea.

Sclerostomysearch for term

A surgical procedure in which a tiny drainage hole is made in the sclera (white part of the eye) in order to lower eye pressure.

Steroid Medicationsearch for term

Corticosteroids mimic the effects of hormones the body produces naturally. When prescribed in doses exceeding the body’s usual levels, steroids suppress inflammation as well as the body’s immune system, helping to control conditions in which the body’s immune system mistakenly attacks its own tissues.

Strabismussearch for term

This refers to misalignment of the eyes. Normally the two eyes are pointed in the same direction. In strabismus, one eye looks straight ahead while the other may point inward, outward, up or down.

t
Thyroid Diseasesearch for term

In this autoimmune condition a body’s immune system stimulates enlargement of the muscles that move the eyes. This results in bulging of the eyes, retraction of the eyelids, double vision, decreased vision and eye irritation.

Tonometrysearch for term

A part of the eye examination in which the doctor measures eye pressure.

Toric Contact Lensessearch for term

Contact lenses that correct for moderate to severe astigmatism.

Toric IOLsearch for term

An intraocular lens used for the reduction of astigmatism, often implanted during cataract surgery.

Trabeculectomysearch for term

A surgical procedure in which eye pressure is lowered by creating a tiny drainage hole in the sclera (white part of the eye) with a small surgical tool.

u
Upper Blepharoplastysearch for term

This surgical procedure eliminates excess skin and puffiness of the upper eyelids.

Uveitissearch for term

The inflammation of the uveal tract, the middle vascular layers of the eye which are critical to its normal function.

v
Visual Field Testsearch for term

A part of the eye examination in which the side, or peripheral, vision is tested.

Vitrectomysearch for term

A surgical procedure which helps treat several retinal conditions, such as retinal detachment, by removing the jelly (vitreous) in the inside of the eye.

Vitreoussearch for term

The clear gel which fills the middle of the eye and attaches to the retina.

w
WaveScansearch for term

State of the art laser vision correction system which allows surgeons to measure and correct visual imperfections that were previously undetectable with the
technology commonly used to prescribe glasses and contact lenses.

x
X-Chrome Contact Lensessearch for term

A red contact lens worn in the non-dominant eye to overcome color confusion and the inability to differentiate between red and green (color blindness). The gene that causes color deficiency is on the X chromosome.