Ishiharapiirustukset

Ishiharapiirustukset, often referred to as Ishihara plates, are a type of pseudoisochromatic plate used to detect red-green color blindness. They were developed by Japanese ophthalmologist Shinobu Ishihara in 1917. The plates consist of a series of colored dots, typically arranged in circles, where individuals with normal color vision can discern certain numbers or patterns, while those with color vision deficiencies cannot.

The underlying principle of the Ishihara test relies on the subtle differences in color perception between individuals. The dots are chosen to have similar brightness and hue saturation, making them difficult to distinguish for someone with color blindness. The specific numbers and patterns presented vary across the plates, with some designed to identify different types and severities of red-green color vision deficiency.

The Ishihara test is widely used in ophthalmology, optometry, and as a screening tool in various professions where accurate color perception is crucial, such as piloting or certain manufacturing roles. Its simplicity, speed, and ease of administration have made it a standard diagnostic method. The test is generally considered reliable for identifying red-green color blindness, although it may not detect all forms of color vision deficiency.