Color blindness or color vision deficiency impacts on a person’s life in various different ways.
In childhood, the condition may lead to learning difficulties if it goes identified and teaching methods are not modified accordingly. In later life, difficulty differentiating between colors can hamper a person’s ability to carry out normal daily activities such as driving, for example. In addition, color vision deficiency can have a profound influence on a person’s choice of occupation.
Certain occupations are not suitable for people with color vision deficiency and people with the condition may even be prohibited from working in some environments. Examples range from careers that involve mixing paint through to those that require a person to operate machinery, deal with color-coded wires, or read the dashboard correctly while inside a vehicle.
How severely colour blindness can impact on work performance was first documented in 1875 when the Lagerlunda rail crash occurred in Sweden. The crash was caused by misinterpreted signals between a station master and a train driver and resulted in the death of nine individuals. Later, an investigation by an ophthalmologist called Frithiof Holmgren suggested the driver may have been colour blind and that this could have led to the disaster. Professor Holmgren then advocated the exclusion of colour blind individuals from railway occupations and compulsory vision tests were introduced for railway workers.
Several countries including Romania, Singapore and Turkey do not assign driving licences to color blind individuals due to reservations about their ability to interpret traffic lights and warning signals correctly. For similar reasons, people with colour blindness cannot enter a career in aviation. Pilots need to be adept at using colored dashboard instruments when responsible for an aircraft and also need to be able to recognise color coded signals in an emergency or when trying to land a plane using glide-paths on runways. In some countries, people with mild colour vision deficiencies may obtain restricted licences, but in others, licences for these individuals are banned altogether.