Color Blindness: Types, Tests & What Your Results Mean
What Is Color Blindness?
Color blindness (color vision deficiency, or CVD) is the decreased ability to perceive differences between certain colors. About 8% of men and 0.5% of women of Northern European descent have some form of CVD — roughly 300 million people worldwide.
Despite the name, total color blindness (seeing only in grayscale) is extremely rare, affecting about 1 in 33,000 people. Most color-blind individuals see colors, but have difficulty distinguishing between specific shades.
Types of Color Vision Deficiency
Red-Green Color Blindness (Most Common — 99% of cases)
| Type | What's Affected | How Common | What You See |
| Deuteranomaly | Weak green cones | 5% of males | Greens appear muddy/brownish |
| Protanomaly | Weak red cones | 1% of males | Reds appear darker/duller |
| Deuteranopia | No green cones | 1% of males | No green perception |
| Protanopia | No red cones | 1% of males | No red perception |
Blue-Yellow Color Blindness (Rare)
| Type | What's Affected | How Common |
| Tritanomaly | Weak blue cones | Very rare |
| Tritanopia | No blue cones | Extremely rare |
Complete Color Blindness
- Achromatopsia — No functioning cones at all. Sees only in shades of gray. Affects ~1 in 33,000.
How Does Color Vision Work?
The human retina contains two types of light-sensitive cells:
- Rods (~120 million) — Detect brightness, work in low light
- Cones (~6 million) — Detect color, require bright light
There are three types of cones, each sensitive to different light wavelengths: short (blue), medium (green), and long (red). Color blindness occurs when one or more cone types are absent, malformed, or reduced in sensitivity.
Can You Develop Color Blindness?
While most CVD is genetic (inherited via the X chromosome, which is why men are affected 16x more than women), acquired color blindness can result from:
- Aging (lens yellowing reduces blue perception after 50)
- Certain medications (especially Plaquenil and ethambutol)
- Eye diseases (glaucoma, macular degeneration, diabetic retinopathy)
- Chemical exposure
Testing Your Color Vision
Clinical Tests
- Ishihara Test — The classic dotted circle plates
- Farnsworth D-15 — Arranging color chips in order
- Anomaloscope — The gold standard (matches red and green lights)
Digital Tests (Like VIGILFI's Color Perception Test)
Our Color Perception test isn't a clinical color blindness diagnostic — it measures color discrimination ability on a continuous scale. However, if you consistently score below Level 8-10, it may suggest reduced color sensitivity worth investigating with an eye care professional.
Living With Color Blindness
Color blindness is not a disability for most people — it's an inconvenience. Modern accommodations include:
- Color-blind-friendly design in apps and websites
- EnChroma glasses (helps some types of CVD)
- Smartphone apps that identify colors in real-time
Test Your Color Perception
Take the VIGILFI Color Perception test to measure how precisely your eyes can distinguish between similar hues. The test progressively reduces the color difference until you can no longer detect it. Most people reach Level 15-20. Reaching Level 25+ indicates exceptional color discrimination.