Ishihara color plates
Pronunciation: ish-ee-HAH-rah
Standardized color vision test using numbered plates with colored dots to detect red-green color deficiencies.
Full Definition
Ishihara color plates are the most widely used screening test for color vision deficiencies, particularly red-green color blindness. The test consists of a series of plates containing colored dots arranged to form numbers or patterns that are visible to individuals with normal color vision but difficult or impossible for those with color deficiencies to perceive. In neuro-ophthalmology, acquired color vision defects may indicate optic nerve disease, retinal pathology, or cortical lesions. Unlike congenital color deficiencies, acquired defects often affect blue-yellow discrimination and may be asymmetric between eyes. The test is quick to administer but has limitations in detecting subtle acquired defects or blue-yellow deficiencies.
Usage
Usage note: Capitalize as proper noun; results should specify number of plates passed out of total administered.
In Context
- "Ishihara color plates revealed a new red-green defect in the left eye, suggesting optic nerve involvement." — Clinical examination
- "The patient passed all Ishihara color plates, ruling out significant red-green color deficiency." — Screening result