Eye Testing
An eye examination is a battery of tests performed by an ophthalmologist or optometrist assessing vision and ability to focus on and discern objects, as well as other tests and examinations pertaining to the eyes. All people should have periodic and thorough eye examinations as part of routine care by the primary care physician, especially since many eye diseases are silent or asymptomatic.
Eye examinations may detect potentially treatable blinding eye diseases, ocular manifestations of systemic disease, or signs of tumors or other anomalies of the brain.
Ishihara Color Test
Example of an Ishihara color test plate. The numeral "74" should be clearly visible to viewers with normal color vision. Viewers with dichromat or anomalous trichromat may read it as "21", and viewers with achromat may see nothing.