Seen Differently

All patterns

Colour changes

The traffic light is lit. Which one?

Typical visionWith colour changes
Moderate: colours shift toward how a person with this type of colour vision sees them.

Type

Try it

Which bus is pulling in, and is it safe to cross yet?

What's happening

Colour vision relies on three types of cone cell. Inherited colour vision deficiency, far more common in men, changes how reds, greens or blues look from birth and usually stays the same for life. Colour can also change later: cataracts yellow and dim colours, and optic nerve problems can wash them out, often in one eye only.

This simulation is for understanding and empathy. It is not a diagnosis and doesn't replace an eye examination.

What you might notice

Reds and greens merge

Ripe and unripe fruit, or red and green lights, look alike.

Blues and yellows blur

Rarer, but blue and green, or yellow and pink, become hard to tell apart.

Colours look faded

Acquired changes make the world look washed out or yellowed.

One eye differs

Comparing your eyes shows one sees duller colours. That's worth reporting.

Where it gets hard

  • Traffic signals, warning lights and status LEDs.
  • Charts, maps and colour-coded timetables.
  • Telling whether meat is cooked or fruit is ripe.
  • Colour-coded pills, wiring or forms.

Often caused by

Conditions commonly linked to this pattern.

  • Inherited colour vision deficiency (about 1 in 12 men, 1 in 200 women)
  • Cataract
  • Optic neuritis
  • Glaucoma
  • Macular disease
  • Some medicines, including hydroxychloroquine and ethambutol

Treatment and support

Inherited colour deficiency has no cure. Tinted lenses help some people tell certain colours apart but don't restore normal colour vision, and phone apps can name colours through the camera. When colour changes are new, the cause needs checking: cataract surgery often brings colours back dramatically, and medicine-related changes can be monitored.

Looking for research you could join? Search ClinicalTrials.gov or the EU Clinical Trials register.

Get checked the same day if

Colours suddenly look faded in one eye, especially with pain when you move that eye.

If it's sudden or comes with other symptoms, go to an emergency department.

Where to learn more