What is blue-yellow colour vision deficiency?
- Part of the eye
- Short wavelengths
- Group
- Colour vision
- Vision functions involved
- Colour
- Main source
- RNIB
Tritan types involve short-wavelength cone signals. The name is a shorthand: difficulties can involve several combinations, not simply blue versus yellow. People retain colour perception to different degrees.
How blue-yellow colour vision deficiency can affect day-to-day life
You may recognise some of these situations, or none of them. The point is to find help with the things you want to do.
A weather map
Some neighbouring shades may carry unclear meanings.
Use the written forecast and numeric values.
Matching objects
Colour names on products may be more reliable than appearance alone.
Keep original labels or organise by a second cue.
Presentations
A colour legend may not clearly distinguish lines.
Add solid and dashed patterns and name each line directly.
Changes you may notice
- Difficulty separating some blues and greens or other colour combinations.
- Some shades look less distinct. The pattern varies from person to person.
Everyone is different. Symptoms on their own cannot identify a condition.
What to do about a new or sudden changeAssessment and care
Arrange an eye examination if colour perception changes. The eye team may investigate an underlying cause. Do not use an online red-green screening plate to rule out other colour-vision differences.
Different tests answer different questions
Colour-vision assessment may use several tests. Tell the optometrist whether the change is new, whether one eye seems different and which tasks are affected. A demonstration on this site cannot identify the cause.
How vision is affected
These topics explain the parts of vision involved. They do not predict your sight, diagnose anything or show the condition itself.
Colour
Colour helps you tell things apart. Clear labels and patterns make the same information readable without relying on colour.
Open the colour labEveryday support
Inherited blue-yellow deficiency has a different inheritance pattern from common inherited red-green deficiency. Keep the diagnosis separate from achromatopsia, which may also affect detail and light sensitivity.
A question to take to your appointment
Is this an inherited tritan difference or an acquired change, and which tests tell you?Prepare your appointment checklist
Sources and review status
Sources checked 4 October 2026. Educational draft, not yet clinically reviewed. No clinician has endorsed this page. Follow the advice of your own eye-care team.
How this content is prepared