What is a common test used to detect color vision deficiency?

The Ishihara test is commonly employed for detecting color vision deficiency primarily because it was specifically developed for this purpose. This test consists of a series of plates, each featuring a number or shape made up of colored dots, which are designed to be distinguishable by individuals with normal color vision but may be difficult for those with color vision deficiencies to identify. It effectively highlights difficulties in perceiving specific colors, making it a standard method for evaluating an individual’s ability to distinguish between different colors, particularly red and green.

The other options serve different diagnostic functions: the Snellen chart is primarily used to measure visual acuity, the Amsler grid is utilized for assessing central vision and detecting macular problems, and the Contrast sensitivity test evaluates a person's ability to discern between different shades of gray. Each of these tests is crucial for examining various aspects of vision, but the Ishihara test stands out as the specific tool for determining color vision deficiencies.