Question to the Department for Transport:

To ask the Secretary of State for Transport, if she will make an assessment of the potential implications for her policies of the difference in colour vision medical standards between the UK Civil Aviation Authority and the (a) Irish Aviation Authority, (b) Federal Aviation Administration in the US, (c) Civil Aviation Safety Authority in Australia and (d) Civil Aviation Authority of New Zealand; how many pilots have (i) been denied and (ii) lost an initial Class 1 medical certificate due solely to colour vision deficiency in the last five years; what assessment she has made of the potential impact of colour vision medical standards on pilot (A) recruitment and (B) retention.

The UK approach to pilot colour vision testing involves initial screening using Ishihara test plates. Where applicants make a single error, advanced colour vision testing using the Colour Assessment and Diagnosis (CAD) test is required to measure colour vision. The CAD test is one of the few tests designed around a colour dependent aviation task. Applicants with normal or mild impairment are assessed as fit, whilst those with significant colour vision impairment are assessed as unfit. In the absence of evidence published in peer review literature regarding the effectiveness of operational assessments, the CAA only accepts CAD testing for advanced colour vision testing.

We have no evidence to suggest that the UK CAA’s colour vison standards have a significant impact on pilot recruitment. Our aim is to foster a diverse and inclusive sector, while ensuring that the highest standards of aviation safety are maintained. Prospective pilots apply for the initial issuance of a Class 1 medical certificate prior to commencing/being accepted for training to become a commercial pilot. There are currently around 22,000 commercial pilots in the UK. Between 1 April 2021 and 31 January 2026, there were 6,930 initial Class 1 medical examinations in the UK. Only 18 applicants for a Class 1 certificate during this period (0.3% of total) were assessed as unfit solely due to colour vision impairment.

There should also be no impact on pilot retention, since following successful application for a Class 1 medical certificate, a certificate holder would only lose their certificate if they developed a significant condition that may also be associated with colour vision impairment such as macular degeneration with visual loss. Such conditions tend to occur much later in life.

While other regulators may take differing approaches, the UK approach is aligned with international norms. In the absence of peer reviewed evidence regarding the effectiveness of alternative approaches, the UK is engaging with the ICAO-led work referenced in my previous response.