Colour blindness, or colour vision deficiency (CVD), affects around 8% of men and less than 1% of women. In a 2020 briefing CASA stated, “Colour vision deficiency affects about 400 Australian pilots.”
The main cause of CVD is genetic (linked to the X chromosome, of which men typically have one, so if it carries the gene, they will have the condition, whereas women have two, so they need to inherit the gene in both to be colour blind). Other causes can include medication, diabetes, and drug taking. There are many types of colour blindness, with the most common type called “red/green.” However problems can occur across the entire colour spectrum.
Until recently, in Australia, and in most of the world, if pilots can’t pass the initial colour vision test, but…