Ishihara Color Blindness Test 1.5.2.0

The Ishihara test is a color perception test utilized to identify red-green color deficiencies and is part of the successful pseudo-isochromatic plates color vision test category. This test was named after its creator, Dr. Shinobu Ishihara, a professor at the University of Tokyo, who introduced these tests in 1917.

Consisting of various colored plates known as Ishihara plates, each plate contains a circle of randomly colored and sized dots. Embedded within these patterns are dots forming numbers or shapes clearly discernible to individuals with normal color vision, but challenging to detect by those with a red-green color vision defect. Some plates are specifically crafted to reveal numbers exclusively to individuals with a red/green color vision deficiency while remaining imperceptible to those with normal red/green color vision. Although the complete test comprises 38 plates, severe deficiencies can often be identified after only a few plates. Additionally, there are Ishihara tests available with 10, 14, or 24 plates.

• The test comprises various plate designs:
• 1. Demonstration plate: Typically the numeral "12," this plate is visible to all individuals, regardless of their color vision capabilities. It is used purely for demonstration purposes and is generally not included in screening score assessments.
  2. Transformation plates: Individuals with color vision defects perceive a different figure compared to those with normal color vision.
  3. Vanishing plates: Only individuals with normal color vision can identify the figure.
  4. Hidden digit plates: Only individuals with color vision defects can recognize the embedded figure.
  5. Diagnostic plates: These plates aim to identify the type (protanopia or deuteranopia) and severity of color vision defects.