Chapter 13 Eye Diagnostic Procedures
keratometer
An instrument used to measure the curvature of the cornea.
Fluorescein staining
Applying dye eye drops that are a bright green fluorescent color. Used to look for corneal abrasions or ulcers.
Snellen chart
Chart used for testing distance vision named for Dutch ophthalmologist Hermann Snellen. It contains letters of varying size and is administered from a distance of 20 feet. A person who can read at 20 feet what the average person can read at this distance is said to have 20/20 vision.
ophthalmoscopy
Examination of the interior of the eyes using an instrument called an ophthalmoscope. The physician dilates the pupil in order to see the cornea, lens, and retina. Used to identify abnormalities in the blood vessels of the eye and some systemic diseases.
Slit lamp microscopy
Examining the conjunctiva, cornea, iris, and lens of the eye.
ophthalmoscope
Instrument used to examine the inside of the eye through the pupil.
optometer
Instrument used to measure how well the eye is able to focus images clearly on the retina.
keratometry
Measurement of the curvature of the cornea using an instrument called a keratometer.
tonometry
Measurement of the intraocular pressure of the eye using a tonometer to check for the condition of glaucoma. Generally part of a normal eye exam for adults.
Visual acuity (VA) test
Measurement of the sharpness of a patient's vision. Usually, a Snellen chart is used for this test in which the patient identifies letters from a distance of 20 feet.
Fluorescein angiography
Process of injecting a dye (fluorescein) to observe the movement of blood and detect lesions in the macular area of the retina. Used to determine if there is a detachment of the retina.
Color vision tests
Use of polychromic (multicolored) charts to determine the ability of the patient to recognize color.
Refractive error test
Vision test for a defect in the ability of the eye to accurately focus the image that is hitting it. Refractive errors result in myopia and hyperopia.