The clarity or clearness of vision, a measure of how well a person sees.
- Visual acuity test
This test measures how well you see at various distances. It is the familiar eye chart test. The eye chart itself — the usual one is called Snellen’s chart — is imprinted with block letters that line-by-line decrease in size, corresponding to the distance at which that line of letters is normally visible. The letters […]
- Visual contrast sensitivity
The ability to perceive differences between an object and its background.
- Visual evoked response
VER. A type of electrophysiologic retinal testing done to evaluate the retina and optic nerve by measuring the electrical potential resulting from a visual stimulus.
- Visual field
Hydroxychloroquine is classified as an anti-malarial drug. It is similar to chloroquine (Aralen) and is useful in treating several forms of malaria as well as lupus erythematosus and rheumatoid arthritis. Its mechanism of action is unknown. Malarial parasites invade human red blood cells. Hydroxychloroquine may prevent malarial parasites from breaking down (metabolizing) hemoglobin in human […]
- Visual field
The entire area that can be seen when the eye is directed forward, including that which is seen with peripheral vision. The visual field can be tested to measure the extent and distribution of the field of vision. The test may be done by a number of methods including what are termed confrontation, tangent screen […]