Deuteranomaly
Reduced sensitivity to green light, the most common form.
What Deuteranomaly means
Deuteranomaly means the green-sensitive cones in your eyes are shifted toward red. You still see colour in three dimensions, but greens, yellows, oranges and reds can look muddier and harder to tell apart. It is the most common type of colour blindness and is usually mild, many people never notice it.
What it can look like day to day
- Ripe vs. unripe fruit can be hard to judge
- Red text on a green background loses contrast
- Traffic lights are read by position, not colour
- Green and brown, or blue and purple, can be confused
How common is it?
~5% of men (about 1 in 20). Colour vision deficiency overall affects roughly 1 in 12 men and 1 in 200 women, see the full prevalence breakdown.
Can glasses help?
For deuteranomaly, colour-correction glasses are most likely to help, mild-to-moderate anomalous trichromacy is exactly the case where the filters can boost red-green contrast. They don't add missing cones or "cure" anything. Read the honest glasses comparison.
How to test for Deuteranomaly
Start with the free online color blind test or the focused red-green test. For a diagnosis, an eye-care professional uses calibrated plates, an anomaloscope or an arrangement test. Want to see the difference? Try the colour blindness simulator.