Colour Blindness Test
Take our free online colour blindness test featuring canvas-rendered Ishihara-style colour plates. Screen for protanopia (red-blind), deuteranopia (green-blind), and tritanopia (blue-yellow) colour vision deficiencies. View each colour plate, enter the number you see, and receive a detailed analysis with accuracy score, likely deficiency type, severity estimate, and plate-by-plate breakdown - all running locally in your browser with no signup required.
Interactive Ishihara-style colour plate test. View each plate, enter the number you see, and receive a result with possible colour vision deficiency type. All processing runs locally in your browser - no images are uploaded.
How the Test Works
- ●You will be shown 10 colour plates, each with a number made of coloured dots
- ●Type the number you see in each plate, or skip if you see nothing
- ●At the end, you'll get a result summary with possible colour vision deficiency type
- ●This is an educational screening tool, not a clinical diagnosis
For best results, use a calibrated display in a well-lit room.
Why Use Our Colour Blindness Test?
Ishihara-Style Colour Plate Tests
Our colour blindness test uses canvas-rendered Ishihara-style colour plates with dot patterns that simulate the standard Ishihara test format. Each plate displays a number made of coloured dots against a contrasting dot background, designed to screen for common colour vision deficiencies including protanopia, deuteranopia, and tritanopia.
Private and Secure - No Uploads
The colour blindness test runs entirely in your browser. All colour plates are generated on-device using canvas rendering - no images are downloaded, no data is uploaded, and no results are stored on any server. Your test answers remain completely private on your device.
Colour Blindness Test Online - No Installation
Use the colour blindness test directly in any modern browser on desktop, tablet, or mobile. No app download, no plugin, no account needed - just open the page and start the test. The canvas-rendered plates adapt to your screen size automatically.
Free Educational Screening Tool
The colour blindness test is completely free with no signup, no ads, and no usage limits. Results include a detailed analysis with likely deficiency type, severity estimate, and plate-by-plate breakdown. Note: This is an educational screening tool and not a clinical diagnosis.
Common Use Cases for Colour Blindness Test
Personal Awareness and Self-Screening
Many people go their entire lives without knowing they have a colour vision deficiency. Use our colour blindness test as a quick self-screening tool to gain awareness about your colour perception. Early awareness can help you understand everyday challenges like reading traffic lights, matching clothes, or interpreting colour-coded charts.
Career Guidance and Job Requirements
Certain professions require normal colour vision - including pilots, electricians, graphic designers, police officers, railway workers, and medical professionals. Use our colour blindness test as an initial screening to help guide career decisions before undergoing formal testing with an optometrist.
Educational Demonstration for Students
Teachers and professors can use the colour blindness test as a classroom demonstration to help students understand colour vision deficiencies. The interactive plate-by-plate format makes it easy to explain how different types of colour blindness affect perception of numbers and patterns in everyday life.
Web and Graphic Design Accessibility
Designers and developers can use the colour blindness test to better understand how colour vision deficiencies affect user experience. The plate results help illustrate the importance of accessible colour choices, contrast ratios, and using non-colour indicators (icons, text labels, patterns) in design.
Family History and Genetic Screening
Colour blindness is often hereditary and passed through the X chromosome, affecting approximately 1 in 12 men and 1 in 200 women. If you have a family history of colour blindness, use this test as a simple initial screening tool for yourself and family members.
Pre-Employment Colour Vision Check
Before pursuing a role that requires good colour discrimination, use our colour blindness test as a preliminary check. While this test does not replace a professional Ishihara test administered by a qualified optometrist, it can help you identify potential issues early in your job search.
Understanding the Colour Blindness Test
What is the Ishihara Colour Blindness Test?
The Ishihara test is the most widely used colour vision screening test worldwide, developed by Dr. Shinobu Ishihara in 1917. It consists ofcolour plates (often called Ishihara plates) that contain a circle of coloured dots appearing random in colour and size. Within the dot pattern, a number is embedded using dots of a different colour. People with normal colour vision can easily see the number, while those with colour vision deficiencies may see a different number or no number at all. Our colour blindness test uses canvas-rendered digital plates that simulate this format for educational screening purposes.
How Our Colour Blindness Test Works
- View the Colour Plate: Each plate displays a field of coloured dots generated using canvas rendering. A number made of dots in a contrasting colour is embedded within the pattern. The dots vary in size, hue, saturation, and lightness to simulate the classic Ishihara test format.
- Enter What You See:Type the number you see in each plate into the input field. If you don't see any number, you can skip the plate. Each plate is designed to test a specific aspect of colour perception - including red-green sensitivity (protanopia/deuteranopia) and blue-yellow sensitivity (tritanopia).
- Review Your Results:After completing all 10 plates, you'll receive a detailed analysis showing your accuracy percentage, likely colour vision deficiency type (if any), estimated severity, and a plate-by-plate breakdown comparing your answers with expected results for each plate.
Types of Colour Vision Deficiency
- Protanopia (Red-Blind): Reduced sensitivity to red light. Affects approximately 1% of males. People with protanopia have difficulty distinguishing between red, green, and brown tones. Red may appear as black or dark grey. The red-sensitive cones (L-cones) in the retina are missing or malfunctioning.
- Deuteranopia (Green-Blind): Reduced sensitivity to green light. The most common form of colour blindness, affecting approximately 1% of males. People with deuteranopia have difficulty distinguishing between shades of red, green, yellow, and brown. The green-sensitive cones (M-cones) are affected.
- Tritanopia (Blue-Yellow): Reduced sensitivity to blue light. Much rarer than red-green colour blindness, affecting approximately 0.01% of the population equally across sexes. People with tritanopia have difficulty distinguishing between blue and green, and between yellow and violet. The blue-sensitive cones (S-cones) are affected.
- Anomalous Trichromacy: The most common type of colour vision deficiency where one type of cone has altered sensitivity rather than being completely missing. Protanomaly, deuteranomaly, and tritanomaly are milder forms where colour discrimination is reduced but not absent.
Limitations and Important Notes
This colour blindness test is an educational screening tooldesigned for informational purposes only. It does not replace a comprehensive eye examination or a professional Ishihara test administered by a qualified optometrist. Results may be affected by several factors including: monitor calibration, screen brightness, ambient lighting, display technology (LCD, OLED, CRT), and screen colour temperature. For an accurate clinical diagnosis of colour vision deficiency, please consult an eye care professional who will use standardised Ishihara test booklets under controlled lighting conditions.
Frequently Asked Questions About Colour Blindness Test
A colour blindness test is a screening tool that helps identify colour vision deficiencies. Our colour blindness test uses canvas-rendered Ishihara-style plates - circular fields of coloured dots with embedded numbers. Depending on your colour perception, you may see different numbers or no numbers at all in each plate. The test screens for protanopia (red-blind), deuteranopia (green-blind), and tritanopia (blue-yellow) colour vision deficiencies.
Our colour blindness test is designed as an educational screening tool and can provide a general indication of colour vision status. However, it does not replace a professional Ishihara test using standardised printed plates under controlled lighting conditions. Factors like monitor calibration, screen brightness, and ambient lighting can affect results. For a definitive diagnosis, please consult an optometrist.
The main types of colour vision deficiency are: Protanopia (red-blind) - reduced sensitivity to red light; Deuteranopia (green-blind) - reduced sensitivity to green light, the most common type; Tritanopia (blue-yellow) - reduced sensitivity to blue light, much rarer; and Anomalous Trichromacy - milder forms where colour discrimination is reduced but not absent. Colour blindness affects approximately 1 in 12 men and 1 in 200 women worldwide.
Yes - our colour blindness test is 100% free with no signup, no account, and no usage limits. Take the test as many times as you need, share it with family members, or use it for educational demonstrations. There are no premium tiers, no hidden restrictions, and no data collection.
Yes, the colour blindness test is fully responsive and works on mobile browsers. The canvas-rendered plates automatically adapt to your screen size. However, for best results, we recommend using a desktop or laptop monitor with accurate colour calibration in a well-lit room. Small screens or devices with colour-shifting screen protectors may affect test accuracy.
Yes, women can be colour blind, though it is much less common. The genes for red-green colour blindness are carried on the X chromosome. Since women have two X chromosomes, they need to inherit the deficiency gene from both parents to be affected, while men only need one copy. Approximately 1 in 12 men (8%) and 1 in 200 women (0.5%) have some form of colour vision deficiency.
Most forms of colour blindness are genetic and cannot be cured. However, there are aids available such as colour-correcting glasses (e.g., EnChroma) that can enhance colour discrimination for some people with certain types of colour blindness. These glasses do not cure colour blindness but can help improve colour perception. For acquired colour blindness (caused by aging, eye disease, or medication), treating the underlying cause may improve symptoms.
Your score is calculated as the percentage of plates you correctly identified out of the total 10 plates. For plates where a number is expected, your answer is compared to the expected number. For the hidden plate where no number should be visible, answering "nothing" counts as correct. Based on which plates you miss, the test estimates the likely type of colour vision deficiency (protanopia, deuteranopia, or tritanopia).
If our colour blindness test suggests a possible colour vision deficiency, we recommend scheduling a comprehensive eye examination with an optometrist or ophthalmologist. A professional can administer standardised Ishihara tests and other diagnostic assessments under controlled conditions to provide a definitive diagnosis and discuss any implications for your daily life or career.