Color Blind Test
Screen your colour vision with Ishihara-style plates generated entirely in your browser — no images, no uploads.
Color Vision Screening Test
This test uses Ishihara-style plates generated in your browser to screen for potential color vision differences. It is not a medical diagnosis.
How to Use Color Blind Test
8 circular colour plates are shown one at a time. Each plate contains a hidden number pattern.
Look at the plate and identify the number formed by dots within it. Take your time — there is no time limit.
Choose the number you see from the options below the plate. If you cannot distinguish any number, select "None".
After all 8 plates, receive an indication of your colour vision based on how many you identified correctly.
If the test suggests a possible colour vision difficulty, visit an eye care professional for proper clinical testing.
Features & Benefits
Ishihara-Style Plates
Classic pseudoisochromatic plate design — dots of similar brightness but different hue form hidden numbers.
Fully In-Browser
All plates are generated on your device using Canvas API — no external images, no uploads, completely private.
Scored Result
After 8 plates, receive a colour vision indication: normal, possible red-green difficulty, or possible deficiency.
Mobile Optimised
Canvas plates scale to your screen. Tap answer buttons on mobile — no zooming or scrolling required.
About Color Blind Test
What Is Colour Vision Deficiency?
Colour vision deficiency (commonly called colour blindness) is a reduced ability to distinguish between certain colours. The most common form affects red-green discrimination, impacting approximately 8% of males and 0.5% of females with Northern European ancestry. It is usually hereditary, caused by absent or abnormal cone photoreceptors in the retina.
Types of Colour Vision Deficiency
- Deuteranopia / Deuteranomaly — Red-green deficiency (missing or reduced M-cones). The most common type.
- Protanopia / Protanomaly — Red deficiency (missing or reduced L-cones). Reds appear very dark.
- Tritanopia / Tritanomaly — Blue-yellow deficiency (missing or reduced S-cones). Rare, affects less than 0.01% of the population.
- Achromatopsia — Total colour blindness (complete absence of cones). Extremely rare.
How Ishihara Plates Work
Pseudoisochromatic plates use dots of similar lightness but different hue. People with normal colour vision see a number formed by the foreground dots against the background dots. People with colour deficiency cannot distinguish the hues and see only a uniform field — the number is invisible. The test was developed by Dr. Shinobu Ishihara in 1917 and remains the global standard for colour vision screening.
Important Disclaimer
This browser-based test is a screening tool only. Results are affected by screen calibration, ambient lighting, and individual display characteristics. A formal diagnosis requires a clinical examination by an optometrist or ophthalmologist using printed plates under standardised lighting conditions.
Frequently Asked Questions
Colour vision deficiency (commonly called colour blindness) is a reduced ability to distinguish between certain colours. The most common form is red-green colour blindness, affecting about 8% of men and 0.5% of women with Northern European ancestry. It is caused by absent or abnormal cone cells in the retina and is usually inherited.
Ishihara plates are a pseudoisochromatic colour test developed by Dr. Shinobu Ishihara in 1917. Each plate contains a pattern of dots in two colours of similar brightness — a number is visible to people with normal colour vision but not to those with colour deficiency (or vice versa). The test primarily screens for red-green colour vision deficiency.
This browser-based screening uses programmatically generated plates and is intended to give a broad indication only. Screen colour calibration, ambient lighting, display brightness, and individual monitor differences all affect accuracy. An optometrist using printed clinical Ishihara plates in controlled lighting is required for a definitive diagnosis.
There is currently no cure for inherited colour vision deficiency. However, certain tinted lenses and glasses (e.g., EnChroma) can enhance colour contrast for some individuals. People with colour deficiency often adapt well and lead normal lives. Many careers also accommodate colour vision requirements through testing and reasonable adjustments.