Basic Medical/ Vision Terms Flashcards
Accommodation
The ability of the eye to focus from distance to near
Ametropia
Condition in which, when accommodation is relaxed, parallel light rays entering the eye do not focus on the retina. (Ex: myopia, hyperopia and astigmatism).
Also a non-specific term that means the patient has a refractive condition.
Aphakia
Absence Of Crystalline Lens
When a cataract progresses to the degree that it interferes with vision, the crystalline lens can be surgically removed.
Aqueous Humor
Clear fluid produced in the ciliary processes and fills the space from the posterior cornea to the anterior vitreous; maintains the intraocular pressure; nourishes the cornea, iris, and lens
Asepsis
Practice to reduce/ eliminate contaminants (such as bacteria, viruses, fungi and parasites) from entering the operative field in surgery or medicine to prevent infection
Astigmatism
Image focused at two points, cornea longer in one meridian than another
• “football-shaped” cornea
• Different power of lens to correct each meridian
corrected by use of cylindrical eyeglasses or contact lenses (spherical or toric)
Base Curve
Measurement of the back curvature of a lens
Bifocal
Lens that provides both distance and near correction.
Binocular Vision
Simultaneous use of both eyes.
The ability to maintain visual focus on an object with both eyes creating a single visual image.
Biomicroscope
Instrument used for observing a fit of contact lenses, checking for foreign bodies in the eye and looking at all parts of the front of the eye including eyes, lids and lashes.
Bulbar
Conjunctiva covering the eyeball that protects the sclera (white part of eye).
Cataract
When crystalline lens gets hard or cloudy with age.
Is a clouding of the eye’s lens and is the leading cause of blindness.
Chief Complaint
Patient’s reason for the office visit
Concave Lenses
Lens that is thinner in the center and thicker at the edges; parallel light passing through this type of lens is diverged, or refracted, away from the midline. Also known as a minus lens
Confrontation Fields
Technique used to screen for visual field defects using the fingers of the examiner
Patient looks directly at examiners eye or nose and testing each quadrant in the patient’s visual field by having them count the number of fingers the examiner are showing.
Convex Lenses
A lens that is thicker in the center and thinner at the edges; parallel light rays passing through this type of lens are refracted by each surface to converge toward the midline behind the lens. Also known as a plus lens
Diopter
Unit of refractive power; abbreviated with the letter “D”. Measure of how much an ophthalmic lens refracts or bends light that can be used to determine its power. (Ex: a one-diopter lens will focus light at one meter.)
Disinfection
To destroy harmful bacteria and viruses.
Edema
Swelling of tissues due to fluid influx
Emmetropia
Image will focus on retina when accommodation is relaxed. No lenses needed 20/20 or “perfect vision”
Fluorescein/ Fluorescein Sodium
Most commonly used ophthalmic dye which is available in liquid form or impregnated on dry, paper filter strips.
Dye used topically to evaluate corneal integrity and intravenously to evaluate blood vessel integrity. Tear film quality is best observed when a fluorescein drop is used.
Fovea/ Fovea Centralis
Central (1.5 mm) area of the macula; responsible for the sharpest vision, fine discriminations and high visual acuity. The area of the macula that is used for daytime and color vision also the area of highest concentration of cone cells and no blood vessels.
Fundus
Interior portion of eyeball that can be seen on ophthalmoscopy or photography. Includes the retina and optic disc.
Glaucoma
Intraocular pressure disease. Group of eye conditions that damage the optic nerve.
A group of diseases that can damage the eye’s optic nerve and result in the vision loss and blindness. It occurs when the normal fluid pressure inside the eyes slowly rises.
Hyperopia/ Farsightedness
Image focused BEHIND retina, cornea too flat or eyes too short. Corrected with plus lenses.
Binocular Indirect Ophthalmoscope/ Indirect Ophthalmoscope
An instrument that is worn on the examiners head and used to view the back of the eye. Used to take stereoscopic views of the fundus.
Intraocular Pressure
Fluid pressure maintained in the eye by the aqueous humor; measured with a tonometer.
IOP
Intraocular Pressure
Keratometer
Instrument used to measure the corneal curvature
Lensometer
Instrument used for determining the power of an eyeglass or contact lens. Measures back vertex power which includes sphere and cylinder power.
Macula
Central portion of the retina surrounding the fovea; responsible for sharp clear central vision. Also for seeing detail.
Macular Degeneration
Disease of the eye, involving loss of structure and function (deterioration) of the macula.
Largest cause of irreversible blindness.
Dry and wet types.
In dry macular degeneration, the center of the retina deteriorates.
With wet macular degeneration, leaky blood vessels grow under the retina.
Monocular
Use of only one eye
Myopia/ Nearsightedness
Image focused IN FRONT of retina, eyes too long. Corrected with minus lenses.
Ocular Adnexa
Part of the external part of the eye examination to rule out any abnormalities or ocular conditions in the adjacent structures of the eye (eyelids, lashes, eyebrows, lacrimal apparatus, tarsal plates, orbit, extraocular muscles and conjunctiva).
Ophthalmoscope
An instrument used in examining the interior of the eye
Palpebral
Conjunctiva that lines the inside of the eyelids
Pantoscopic Angle or Tilt
The angle the frame front makes with the temples when viewed from the side; lower rims are closer to the face than the upper rims.
PD
Pupillary distance
Perimetry
The study of the visual fields
