Optometry Terms: Q-U
Radial Keratotomy - is a refractive surgical procedure to correct myopia discovered by accident by Svyatoslav Fyodorov who was forced to take out glass from his patient’s eye. After making incisions radiating around the pupil like spokes in a wheel, he was able to take out all the glass. He also discovered that the vision in that eye had significantly improved after it had healed.
Retina – is a tissue lining found in the surface of the eye, which is light sensitive. The retina’s function is similar to that of film as the optics of the eye create an image of the visual world on it. Any light striking the retina begins a series of events that translate into information that becomes transferred to various visual centers of the brain through the fibers of the optic nerve.
Retinal Detachment - is an eye disorder involving the peeling away of the retina from its underlying layer of support tissue.
Retinoscope - shines light into the retina of a patient’s eye in order to observe the reflection of the light off the retina of the patient.
Rod – They are photoreceptor cells located in the retina area of the eye. They are able to function in less intense light. This is the opposite than cones which is the other type of visual photoreceptor.
Schlemm’s Canal - is a circular channel located in the eye whose job it is to collect aqueous humor from the anterior chamber. The channel delivers it into the bloodstream using the anterior ciliary veins.
Sclera - known as the white or white of the eye, is the opaque, fibrous, outer layer of the eye that contains both collagen and elastic fiber. It acts as the protective membrane of the eye.
Slit lamp - is an instrument that use a high-intensity light source designed to focus and shine a thin sheet of light into the eye. When used along side a biomicroscope the lamp aids the examination of the anterior segment, or frontal structures and posterior segment, of the human eye. This includes the eyelid, sclera, conjunctiva, iris, natural crystalline lens, and cornea.
Snellen chart – This is an eye chart used by eye care professionals to help measure visual acuity.
Strabismus - is a condition in which the eyes are not properly aligned with each other.
Sty, Stye - A sty is an acute infection of the eyelids’ secretory glands. This is a common infection that is the result of blocked glands within the eyelid. If a gland becomes blocked, there may be a blockage of oil which can extrude through the wall of the gland and form a lump. This lump can become red, painful, and nodular.
Trabecular Meshwork – is an area of tissue in the eye located around the base of the cornea, near the ciliary body, and is responsible for draining the aqueous humor from the eye via the anterior chamber (the chamber on the front of the eye covered by the cornea).
Trifocals - are eyeglasses that have 3 regions to correct for distance, intermediate (arm’s length), and near vision.
Uvea - Part of the eye, made up together of the iris, the choroid of the eye, and the ciliary body.