Ophthalmic Terminology and Vocabulary

Accommodation

Adjustment of the eye for seeing at different distances via lens shape changes.

Age Related Macular Degeneration

Macular disease that occurs in the elderly, a leading cause of blindness.

Albinism

A genetic condition characterized by an absence of pigment cells either throughout the body, or restricted to the eye, usually associated with decreased vision, nystagmus, light sensitivity.

Amaurosis Fugax

Temporary blindness, often monocular.

Amblyopia

Loss of vision without any identifiable organic cause, usually due to uncorrected refractive error.

Ametropia

Any refractive error of the eye can be called ametropia.

Amsler Grid

A chart with horizontal and vertical lines for testing macular distortion.

Anaphylactic Shock

State of collapse resulting from injection of a substance to which a person has become sensitized.

Aneurysm

An outpouching or sac in the artery as seen in diabetic retinopathy as a microaneurysm.

Angle-Fixated lens

Intraocular lenses surgically fixated in the angle of the anterior chamber.

Aniridia

Congenital absence of the iris.

Anisocoria

Difference of the diameter of the pupils.

Anterior Chamber

The distance between the cornea and the lens, very shallow in narrow angle glaucoma.

Aphakia

Absence of the crystalline lens of the eye.

Applanation Tonometry

A form of tonometry in which the force required to flatten a small area of the central cornea is measured.

Aqueous Humor

The clear fluid that is secreted by the ciliary processes and fills the anterior and posterior chambers of the eye.

Artifact

An effect produced by improper technique or poor subject quality that degrades the photographic image.

Asteroid Hyalosis

Calcium deposits in the vitreous. Usually do not impair vision.

Astigmatism

Refractive error that prevents light rays from coming to single point of focus due to varying refractive indices in different meridians.

Attenuation

Narrowing of a vessel.

Basal Cell Carcinoma

The most common malignant lid tumor; has a characteristic appearance of a pit surrounded by raised 'pearly' edges.

Bilateral

Pertaining to or located on both sides of the body.

Binocular Vision

Ability of the eyes to focus on one object and to fuse the two images into one.

Blepharitis

Inflammation of the eyelids.

Blind Spot

The site of the optic disc where there are no photoreceptors.

Blindness

In the US, usually defined as central visual acuity of 20/200 or less in the better eye after correction, or a visual field of less than 20-30 degrees.

Blowout Fracture

An injury due to blunt trauma, in which orbital bones are broken.

Bowman's Membrane

A layer of the cornea, located between the corneal epithelium and the corneal stroma, acts as an anchor for the corneal epithelium.

Bulbar Conjunctiva

The globe portion of the conjunctiva.

Capsule

A thin membrane that encloses the crystalline lens.

Cataract

An opacity of the lens, usually due to aging.

Central Visual Acuity

Detailed vision, as in reading.

Chalazion

A nontender lump that may become visible on the outer lid; due to long term infection of a meibomian gland.

Choriocapillaris

The meshwork of capillaries in the middle tunic of the globe.

Chorioretinitis

Inflammation of the choroid and retina.

Choroid

The highly vascular coat of the eye that nourishes the outer layer of the retina, part of the uveal tract.

Choroiditis

Inflammation of the choroid.

Ciliary Body

Circular muscle behind the eye that influences accommodation, part of the uveal tract.

Ciliary Processes

Fingerlike projections from the ciliary body that produce aqueous humor and provide attachment for the zonules.

Coloboma

Congenital cleft due to the failure of some portion of the eye to complete growth.

Congenital

Present at birth.

Conjunctiva

The thin, translucent mucous membrane that lines the inner surface of the eyelids (palpebral) and the outer surface of the globe (bulbar), except for the cornea.

Conjunctivitis

An inflammation of the conjunctiva.

Contraindication

Any condition that renders a particular treatment, medication, or medical device inadvisable for a particular patient.

Convergence

The process of directing the visual axes of the eyes to a near point, resulting in a turning inward of the eyes.

Cotton Wool Spots

Microinfarctions of the nerve fiber layer of the retina.

Cycloplegic

A drug that temporarily puts the ciliary muscle and sphincter muscles of the iris rest and dilates the pupil.

Cylindrical Lens

A segment of a cylinder, the refractive power used to correct astigmatism.

Dark Adaptation

The ability of the retina and pupil to adjust to decreased illumination.

Descemet's membrane

The thin, elastic layer between the corneal stroma and the corneal endothelium, contributing to the rigidity to the cornea.

Diabetes

A disorder of carbohydrate metabolism characterized by hyperglycemia and glycosuria, resulting from inadequate production or utilization of insulin.

Diopters

Unit of measurement of strength of refractive power of a lens.

Diplopia

Seeing one object as two - double vision.

Drusen

Discrete hyaline deposits within Bruch's membrane, beneath the retinal pigment epithelium. Commonly found after age 60.

Edema

Excessive amounts of fluid in the tissue spaces of the body.

Emmetropia

The refractive state of the eye that is able to focus correctly.

Endophthalmitis

An intra ocular inflammation, generally found following an intra ocular surgical procedure.

Enucleation

Complete surgical removal of the eyeball.

Epiphora

Excessive tearing.

Esotropia

A turning in of one or both eyes.

Exophthalmos

A protrusion from the normal position of one or both eyes.

Exotropia

Abnormal turning outward of one or both eyes.

Extravastion

An intravenous injection that did not enter the vein.

Exudates

White opacities representing lipid and blood proteins in or beneath the retina, caused by leakage of retinal vessels.

Exudation

Leakage of fluid between cells out of blood vessels.

Eye Dominance

Preferred eye for monocular fixation.

Field of Vision

The area of useful vision, extending to the periphery in one or both eyes.

Floaters

Particles that are suspended in the vitreous that cast shadows on the retina.

Focal Point

The point at which distant light comes to focus after being reflected or refracted.

Fornix

A loose fold of the conjunctiva, where bulbar and palpebral conjunctiva meet.

Fovea

Area of the macula that produces the sharpest vision.

Fundus

Interior surface of the eyeball, including the optic disc, macula, and retina that can be seen with an ophthalmoscope.

Giant Papillary Conjunctivitis (GPC)

Allergic type of conjunctival inflammation, with large raised bumps on underside of eyelid. Associated with continuous wear of contact lenses.

Glaucoma

Abnormally increased intraocular pressure.

Goblet Cell

The type of cell in the conjunctiva that produces the sticky fluid that comprises the inner most tear film layer.

Gonioscopy

A technique of examining the anterior chamber angle, using a corneal contact lens.

Hemangioma

A type of vascular tumor.

Hematoma

A hemorrhage in the sub-epidermal tissue of the body.

Hemorrhage

Abnormal discharge of blood or accumulation of blood outside a vessel.

Heterochromia

A condition in which the irises of two eyes are different colors.

Histoplasmosis

Infection of the vascular layer of the eye due to a specific fungus.

Hollenhorst plaque

Small yellow cholesterol plaques situated at the bifurcation of retinal arteries.

Human Immunodeficiency Virus (HIV)

The virus that causes AIDS, a deficiency of the immune system, making the patient susceptible to a variety of opportunistic infections of various tissues, including the retina.

Hyperopia

Condition in which focused light rays fall behind the retina (Farsightedness).

Hypertension

A condition in which a patient has a higher blood pressure than normal (>120/80) for his/her age.

Hyphema

Blood in the anterior chamber.

Hypoglycemia

Low blood sugar level, common among patients with diabetes.

Hypopyon

Pus in the anterior chamber.

Hypoxia

A loss of oxygen.

Informed Consent

The process by which, after discussion with the physician about the risks and benefits of a proposed procedure, the patient agrees to undergo a treatment.

Intraocular Lens (IOL)

The artificial implant that replaces the natural lens of the eye.

Intraocular Pressure (IOP)

Fluid pressure within the eye measured in millimeters of mercury.

Iridectomy

Surgical or otherwise removal of all or part of the iris.

Iris Dilator

Radial muscle in the iris that dilates the pupil.

Irvine-Gass Syndrome

Cystoid macular edema occurring after a lens extraction.

Ischemia

A condition in which the supply of blood to a part of the body is severely reduced.

Keratitis

Inflammation of the cornea.

Keratoconus

Abnormal curvature of the cornea, generally steeper curvature.

Keratometer

Device for measuring curvature of the cornea.

Lacrimal Gland

Produces and secretes the aqueous portion of tears, located in the upper outer angle of the orbit.