Eye / Vision Terms & Definitions
We hope to provide every effort to assist you in understanding the various terminology associated with ocular health. Please see below for common terms and definitions you might find helpful. Also, please feel free to contact our office with any questions!
Most nearsighted patients report good near vision but blurred vision at distance. A myopic or nearsighted eye is too strong or too long for light to focus on the retina. A minus powered lens is utilized to focus light and clear the vision of nearsighted patients.
Many farsighted patients report good distance vision, but blurred vision for near point tasks. Often patients with hyperopia will have no complaints of blurred vision, but will experience eyestrain or headaches. A hyperopic or farsighted eye is weaker or too short for light to focus on the retina. A plus powered lens is utilized to focus light and clear the vision of farsighted patients.
A condition where the patient can be both nearsighted and farsighted at the same time. Astigmatism results when the cornea, the front surface of the eye, is not round. In patients with astigmatism the cornea is more shaped like a football than a basketball.
A condition that affects patients over the age of forty. Normal aging changes result in decreased ability to focus for near vision.
The muscles inside the eye becomes weaker, the lens inside the eye becomes more rigid and the patient’s “arms become too short!”
A clouding or opacification of the lens inside the eye. Most cataracts are a result of normal aging processes, but cataracts can result from injuries, radiation and even some systemic medications. Wearing sunglasses can reduce the risk of cataract by blocking harmful ultraviolet (UV) radiation. Vision can be restored for most patients with surgery and an intraocular lens implant.
The macula is a very small area of the retina that gives us our central or sharpest visual acuity. A breakdown of the retinal tissue in this area is called macular degeneration. This degeneration has two forms, wet and dry degeneration. While extensive research is continuing into the causes and cures of both forms of this disease no consistent cure is available at this time. Surgical and medical treatments for wet macular degeneration have been moderately effective. Dietary control and supplements have proven helpful for many patients with dry macular degeneration. While macular degeneration rarely results in true blindness, vision loss from this condition can be very devastating. Often special “low vision” aids like telescopes, microscopes, and electronic devices can restore usable vision to patients with macular degeneration.
GLAUCOMA: At one time it was thought that glaucoma meant loss of vision due to increased intraocular pressure (pressure inside the eye). Research in the last several years has shown glaucoma to be much more complex. It is a disease or condition that attacks the optic nerve, often by high intraocular pressure. The result of this pressure on the nerve is loss of vision. Undetected and untreated glaucoma will cause blindness. With accurate diagnosis and treatment, glaucoma can be very effectively treated and loss of vision prevented. Very often treatment is as simple as taking one or two drops each day to maintain the health of the optic nerve. At times a surgical procedure is necessary to treatglaucoma. Diagnosis of glaucoma can only be made by careful analysis of several factors; including ocular health, intraocular pressure and visual fields.
The eye is comprised of several layers. The innermost layer, the retina, is like the film in a camera. It is where the visual images are captured and sent to the visual areas of the brain. Just below the retina is a layer made up primarily of vascular tissue (blood vessels) that supply nourishment to the retina. If the retina becomes separated or detached from its underlying layer, it loses its blood supply and the cells of the retina can die. This can cause blindness or partial loss of vision. Symptoms include floaters and flashes of light. Retinal detachments must be diagnosed and treated quickly to prevent loss of vision.
A condition that can mimic some symptoms of a retinal detachment. The cause is also similar, reduced blood supply to the retina. Constriction of blood vessels in the very early stages of a migraine may cause partial loss of vision often described as “gray holes” in the field of vision. Often patients will also describe flashing or zig zag lightening bolts in the visual field. The causes or triggers for ocular migraine are too numerous to mention. One common factor for many patients is stress. Unlike the symptoms of a detachment, which will continue until treatment is begun, ocular migraine symptoms usually last only 15 to 30 minutes.
PINK EYE (CONJUNCTIVITIS):
A general term to describe redness in the whites of the eyes resulting from an inflammation or infection. These inflammations or infections fall into three categories:
Bacterial infections – characterized by redness, itchy, at times pain, decreased vision and a mucous discharge.
Viral infections – characterized by redness, burning at times, decreased vision and a watery discharge.
Allergic inflammation – characterized by redness, itching and a water/sticky discharge.