Color Vision Deficiency and Careers — Fields That Require Color Discrimination and How to Check
Fields where color discrimination matters — aviation, maritime, rail, electrical work, police, firefighting, healthcare, design — why standards differ by country and organization, and what to check before choosing a path.
Most jobs have no restrictions for people with color vision deficiency. However, fields where misreading a color signal can lead to accidents may have color vision standards. Standards differ by country, organization, and era, and they change often, so use this article only to get your bearings and always check the organization's latest official requirements.
Fields where color vision standards are common
| Field | Why color matters | Common ways of checking |
|---|---|---|
| Aviation (pilots, air traffic control) | Runway lights, signal lights, instrument displays | Pseudoisochromatic plates; if failed, further tests such as lantern or computerized tests |
| Maritime (navigation) | Judging other vessels' heading from navigation lights (red, green, white) | Pseudoisochromatic plates, lantern tests |
| Rail (train operation) | Signal colors | Pseudoisochromatic plates, further tests |
| Electrical and electronics | Wire and resistor color codes | Employers may run their own checks |
| Some police, fire, and military roles | Identifying signals, vehicles, and markings | Each agency's medical standards |
| Healthcare and clinical laboratory | Reading stained specimens and test strips | Usually no restrictions; duties adjusted |
| Design, printing, textiles | Judging and matching colors | No restrictions; supplemented with tools |
Driver's licenses
In Korea, for example, the Enforcement Decree of the Road Traffic Act lists among its aptitude standards for a driver's license the ability “to distinguish red, green, and yellow.” Most people with red-green color weakness can tell signal colors apart and have no trouble getting a license. For other countries, check with the national licensing authority.
Why standards differ between organizations
- Test methods differ. Some rely on pseudoisochromatic plates alone; some retest those who fail with a lantern test or a computerized color test (e.g., the CAD test used by the UK aviation authority); others test with the actual signals used on the job.
- Required levels differ. Many require the ability to “safely distinguish signal colors,” and people with mild color weakness sometimes pass on further testing.
- Rules change. In several countries, fields that once imposed blanket restrictions have moved to case-by-case, task-based judgments.
Before choosing a path
- Read the official job postings and medical standards for the field you're interested in first. If anything is unclear, contacting the organization directly is the most accurate route.
- Having an eye doctor confirm your exact type and severity (dichromacy or anomalous trichromacy) makes it easier to anticipate how you'll do on further tests. Test methods compared
- Online check results are not accepted as proof by any organization.
Workarounds on the job
- Suggest ways of working that distinguish things by position, number, or pattern instead of color names.
- For screen work, you can use your operating system's color filters and eyedropper tools that read out color values.
- Asking a coworker to double-check only when it matters is also a good approach. Color vision deficiency is often less a matter of ability than of tools and how information is displayed.