👁️ About the Ishihara Color Test
🔴🟢 Red-Green
Tests for the most common type of color blindness
⏱️ Quick
Complete screening in under 2 minutes
📊 8 Plates
Based on the standard Ishihara methodology
🔒 Private
Results stay in your browser only
What is the Ishihara Test?
The Ishihara test is the most widely used color perception test for red-green color deficiency. Developed by Dr. Shinobu Ishihara in 1917, it consists of colored plates containing circles made of dots in randomized colors and sizes. Within each pattern are dots forming a number or shape that people with normal color vision can see, but those with color vision deficiency may not.
The standard Ishihara test contains 38 plates, though screening versions use 14-24 plates. Our online version uses 8 plates optimized for digital screening, providing a quick but effective initial assessment of red-green color vision.
How Color Blindness Works
Color vision depends on specialized cells in your retina called cones. There are three types of cones: red (L), green (M), and blue (S). Color blindness occurs when one or more cone types are absent, defective, or respond differently than normal.
Red-green color blindness (affecting about 8% of men and 0.5% of women) involves the red or green cones. People with this condition may confuse reds, greens, browns, and oranges. Despite the name, affected individuals don't see in black and white - they simply perceive certain colors differently.
What Does Color Blindness Look Like?
People with red-green color blindness don't see the world in grayscale. Instead, they may see red and green as similar brownish or yellowish colors. Greens might appear more yellow, and reds might seem brown or dark. Traffic lights can be distinguished by position rather than color. Purple may look blue since they can't perceive the red component.
Blue-yellow color blindness (much rarer) makes it hard to distinguish blue from green and yellow from violet. Complete color blindness (monochromacy) is extremely rare and results in seeing only shades of gray.
❓ Frequently Asked Questions
What is the Ishihara test?
The Ishihara test is a color perception test for red-green color deficiencies, developed by Dr. Shinobu Ishihara in 1917. It uses colored plates with dots arranged to form numbers that people with normal color vision can see, but those with color blindness may not. It's the most widely used color blindness screening test worldwide.
Am I color blind?
If you have difficulty seeing numbers in our test plates, you may have some degree of color vision deficiency. Common signs include difficulty distinguishing red from green, trouble identifying certain colors, or seeing colors differently than others describe them. Take our test for an initial screening, then consult an eye care professional for a definitive diagnosis.
How accurate is this online color blind test?
Online tests provide a good screening indication but may vary due to monitor calibration, screen brightness, and lighting conditions. For the most accurate results, use a high-quality display, adjust brightness to comfortable levels, and avoid direct sunlight on your screen. For a definitive diagnosis, visit an optometrist or ophthalmologist.
Are online color blind tests accurate?
Online tests are reasonably accurate for screening purposes. Studies show good correlation between online and clinical Ishihara tests when proper conditions are met. However, factors like monitor quality, color calibration, and lighting can affect accuracy. They're best used as a preliminary screening before professional evaluation.
What type of color blindness do I have?
This test screens primarily for red-green color deficiency, the most common type. To determine the specific type (protanopia, deuteranopia, protanomaly, or deuteranomaly), a comprehensive eye exam is needed. An optometrist can perform detailed tests like the anomaloscope to identify your exact type and severity.
How does the Ishihara test work?
Each plate contains dots of varying sizes in different colors. The dots form a number using colors that contrast with the background for normal vision but blend together for those with color blindness. The pattern exploits the specific wavelengths that color blind individuals struggle to distinguish.
Can color blindness be cured?
There is currently no cure for inherited color blindness. However, special glasses (like EnChroma) and contact lenses can help some people perceive a wider range of colors by filtering specific wavelengths. Gene therapy research shows promise for the future. Acquired color vision deficiency may improve if the underlying cause is treated.
Is color blindness hereditary?
Yes, most color blindness is inherited and passed through the X chromosome. Since men have only one X chromosome (from their mother), they are more commonly affected - about 8% of men vs 0.5% of women. Women can be carriers without being color blind themselves. A woman must inherit the gene from both parents to be color blind.
How do they test for color blindness?
Professional testing includes the Ishihara plate test (what we simulate here), the Farnsworth D-15 arrangement test, the anomaloscope (most accurate), and computerized color vision tests. Eye doctors may use multiple tests to determine the type and severity of color vision deficiency.
What is the Ishihara test passing score?
In standard Ishihara tests, correctly identifying 12+ of 14 screening plates typically indicates normal color vision. For our 8-plate test, scoring 7-8 correct suggests normal vision. Missing several plates suggests possible color vision deficiency requiring professional evaluation. There's no "pass" or "fail" - it's a screening tool.
Are all Ishihara tests the same?
No, Ishihara tests come in different versions with 14, 24, or 38 plates. Some plates are designed for specific types of color blindness, some are control plates visible to everyone, and some show different numbers to color blind vs. normal viewers. Our online version uses plates optimized for digital display.
Where can I get a color blind test?
You can take a preliminary screening test here for free! For professional diagnosis, visit an optometrist, ophthalmologist, or optician. Many schools and employers offer color vision screening. Some countries require color vision tests for driver's licenses or certain occupations.
What jobs require color vision tests?
Many careers require normal color vision: pilots, air traffic controllers, electricians (wire colors), train/bus drivers, police officers, firefighters, some military positions, radiologists, pathologists, graphic designers, and quality control inspectors. Requirements vary by country and specific role.
How long does the Ishihara test take?
Our online test takes about 1-2 minutes to complete 8 plates. A standard clinical Ishihara test with 14-38 plates typically takes 5-10 minutes. The test should be done at a comfortable pace - rushing can lead to mistakes even for those with normal color vision.
Can I take this test on my phone?
Yes, but for best results: use a modern smartphone with good color accuracy, increase screen brightness to maximum, take the test in normal indoor lighting (not direct sunlight), and hold the phone at a comfortable viewing distance. Desktop monitors typically provide more accurate color representation.
What do color blind people see?
It varies by type. People with red-green color blindness may see red and green as similar brownish or olive colors. They can still see many colors - their perception just differs for certain hues. They don't see in black and white (that's extremely rare total color blindness). Many people don't realize they're color blind until tested.
At what age should children be tested for color blindness?
Children can be tested from around age 4-5 when they can reliably identify numbers or shapes. Early detection helps teachers and parents adapt learning materials (using shapes instead of just colors, labeling colored items). Testing before school starts is ideal so accommodations can be made from the beginning.
Who invented the Ishihara test?
Dr. Shinobu Ishihara, a Japanese ophthalmologist, developed the test in 1917 while working at the University of Tokyo. He created it originally for military screening. The test became the worldwide standard for color blindness screening and remains the most commonly used method over 100 years later.
Is the Ishihara test accurate?
The Ishihara test is highly accurate for detecting red-green color blindness - it has sensitivity over 95% for moderate to severe deficiency. It's less effective for mild color vision deficiency and doesn't test for blue-yellow deficiency. For complete assessment, additional tests like the Farnsworth D-15 may be used.
How to read/interpret Ishihara test results?
Normal vision: Correctly identify all or nearly all plates. Mild deficiency: Miss 1-3 plates or see them with difficulty. Moderate deficiency: Miss several plates. Severe deficiency: Miss most plates. Some plates show different numbers to normal vs color blind viewers - this helps differentiate types of color blindness.
Can you improve or pass the Ishihara test if color blind?
Memorizing answers won't help as multiple test versions exist with different plates. Some special glasses or colored filters can temporarily help some people see more plates, but these are typically not allowed in official screenings. The test is designed to be unfakeable - there's no way to learn to see the hidden numbers.
Are dogs and cats color blind?
Dogs see in dichromatic vision (similar to human red-green color blindness) - they perceive blue and yellow but have limited red/green perception. Cats have similar vision but with better night vision. Neither sees in pure black and white as commonly believed. Both species rely more on motion and brightness than color.