EYE DICTIONARY:
Accommodation: The ability of the eye to focus on objects that are closer than optical infinity, approx. 20 ft (6 m)
Age Related Macular Degeneration: (ARMD) diseases in which sensory cells of the macula decrease resulting in a loss of central vision: affects older people
Amblyopia: “Lazy eye” a unilateral or occasionally bilateral condition in which the bestcorrected vision is poorer than 20/20 (6/6) in the absence of any obvious structural abnormalities or ocular disease
Anterior Chamber: The small compartment between the cornea and the iris that is filled with clear, transparent fluid calledaqueous humor
Anterior Chamber Angle: The junction of the cornea and the iris, from which aqueous leaves the eye. Also called filtration angle
Applanation: A form of tonometry in which the force required to flatten a small area of the central cornea is measured |
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A-scan Ultrasonography: A diagnostic procedure in which sound waves traveling in a line are used to reveal the position of, and distances between structures within the eye orbit. Also calledA-mode ultrasonography
Astigmatism: A refractive anomaly caused by unequal refraction of light in different meridians, resulting in a distorted and blurred image
Cataract: an opacified or clouded change in the structure of the crystalline lens which results in loss of light and therefore images transmission to the retina
Chalazion: A non-tender lump that may become visible on the outer lid; due to long term inflammation and infection of a meibomian gland
Conjunctiva: The thin transparent membrane lining the exposed eyeball and inside surface of the eyelid
Conjunctivitis: Inflammation of the conjunctiva. May be caused by bacteria, virus, allergens or chemical or UV exposure
Cornea: The front-most surface of the eye. The transparent window and primary focusing lens of the eye
Diabetes Mellitus: A chronic metabolic disorder characterized by the lack of insulin secretion and/ or increased cellular resistance of insulin, resulting in elevated blood levels of simple sugars (glucose) and including complications involving damage to the eyes, kidneys, nervous system and vascular system
Diabetes Type I: IDDM insulin dependent, resulting from destruction of the insulin producing pancreatic islet cells
Diabetes Type II: NIDDM non-insulin dependent, resulting from tissue resistance of insulin
Diabetic Retinopathy: A progression of pathologic changes in the retina; produced by standing diabetes mellitus
Esotropia: A condition in which the eye is turned inwards
Exotropia: A condition in which the eye is turned outwards
Floaters: Small particles of dead cells or other debris that become suspended in the vitreous or particles of the vitreous itself that degenerate in the normal aging process; they cast shadows on the retina and appear as spots or cobwebs
Fluorescein Angiography: A diagnostic photography of retinal vessels that require injection of fluorescein dye
Fundus: A collective term for the retina, optic disc, and macula
Glaucoma: Abnormally increased intraocular pressure resulting in optic nerve damage and loss of visual field
Goldmann Tonometer: An applanation tonometer that measures corneal flattening to determine the intraocular pressure
Gonioscopy: A viewing procedure utilizing a mirror/lens device placed directly upon the cornea that is used to view the drainage area called “the angle” through which aqueous fluid exits the eyeball
Hyperopia: Farsightedness, long-sight (UK): a refractive condition in which light entering the eye is focused virtually behind the retina, resulting in a blurred image in the non-accommodated eye
Iritis: An inflammation of the iris that may cause pain, tearing, blurred vision, small pupils and a red congested eye (uveitis)
Keratoconus: A rare degenerative corneal disease in which the center of the cornea thins and assumes the shape of a cone, seriously affecting the vision
Legal Blindness: A best corrected visual acuity of 20/200 or less or a visual field reduction of 20° or less in the better-seeing eye
Lens: Part of the optical focusing system of the eye, immediately behind the iris. Also
crystalline lens
Lensmeter: An instrument for measuring the prescription of the eyeglass lenses or the power or rigid contact lenses
Macula: The specialized area of the retina closed to the center of the back of the eye that provides detailed central vision
Meibomian Gland: A specialize gland that secretes the oily part of the tear film that lubricates the outer surface of the globe; located on the inner margin of the eyelid (the edge closest to the globe)
Myopia: Nearsightedness, short-sighted (UK) a refractive condition in which light entering the eye is focused short of the retina, resulting in a blurred image
Ophthalmologist: A medical doctor (MD or DO) who specializes in prevention, diagnosing and medical and well as surgical treatment of vision problems and diseases with the eye
Optic Nerve: The nerve that carries electric impulses to the brain’s visual cortex, where they are integrated to produce the sensation of sight
Optometrist: An independent practitioner trained in the prescription of eyeglasses and contact lenses as well as in the detection of eye diseases
Presbyopia: A condition in which the accommodative system fails to allow for the focusing of near objects, resulting from age-related changes in the crystalline lens or ciliary muscle
Ptosis: Drooping of an inability to raise the upper eyelid, caused by the levator
Pterygium: An abnormal wedge-shaped growth on the bulbar conjunctiva that could gradually advance to the cornea and require surgical removal. Most likely related to sun irritation
Pupil: The center hole in the iris through which light must pass to reach the back of the eye
Refraction: In eye care, the process of measuring a patient’s refractive error and the clinical judgement to determine the optical correction needed
Refractive Surgery: A type of corneal surgery that modifies the shape of the cornea to correct some types of myopia, hyperopia and astigmatism
Retina: The inner lining of the eyeball; consists of a layer of light-sensitive cells that convert images from the optical system into electric impulses sent along the optic nerve for transmission to the brain
Strabismus: A misalignment of the eyes that may cause vision to be disturbed; occurs when the extraocular muscles do not work in a coordinated manner
Tonometry: A procedure for the measurement of intraocular pressure. One of the tests for glaucoma
Vertex Distance: The distance from the back surface of an eyeglass lens to the front of the cornea
Visual Field: The height and breadth of space seen by the eye when the gaze is fixated ahead |
