Colour Vision: What Employers Need to Know

Having colour blindness is not widely regarded as a handicap or disability – it is just a difference in the colours that some individuals can see. Employers do, however, need to be aware of the impact of colour vision on their employees, particularly if not being able to tell one colour from another can either put them in danger, or can endanger someone else.

What Jobs Does Colour Blindness Affect

There are many examples of jobs in which having perfect colour vision is important. In the manufacturing sector, for example, being able to identify electrical components by their colour is often necessary, and in the building industry, components, materials, pipes and cylinders may be colour coded. In electronic engineering, getting that colour coding wrong can result in a circuit not working at all, or in it working differently than expected, which can lead to important safety issues.

In transport, train drivers, bus drivers and taxi drivers need to be able to distinguish red lights from green lights. As red-green colour blindness affects about one in twelve of the male population, employers in this sector need to ensure that drivers are tested.

It seems obvious, but employers in the design industry, whether it is interior design, computer aided design, painting and decorating, or website design, need to ensure that the use of colour by colour blind employees is monitored. It may be necessary for employers to supply appropriate aids to make this sort of work possible for someone with colour defects in their vision. Some industries, such as those involved in the manufacture of textiles, dyes and paints, may need to test potential employees for colour blindness to ensure quality control, even though the safety issues are less critical.

What Types of Colour Blindness Should Employers Check For?

There is a wide spectrum of colour blindness and many people with mild colour defects are not aware they have them. For jobs in which colour perception is crucial, the interview process for potential employees should include a colour blindness test as part of a routine health and safety assessment. It is also important for employers to realise that colour blindness is more common in men and it becomes more pronounced after the age of 45. Men over 50 have a 1 in 12 chance of having an inherited defect in their colour vision but an equal chance of having an acquired colour vision problem – so one in 6 potential male employees in this age group may be affected.

The most common type of inherited colour blindness involves an inability to tell the difference between red and green. Colour vision problems that prevent people from telling the difference between other colours, such as blue and yellow, are rarer. Genetic colour blindness tends to be more severe, but there are milder problems that occur because of diseases such as diabetes and heart disease, and other diseases that affect the quality of circulation in the back of the eye. Most of the colour vision problems that arise during a person’s lifetime affect blue/yellow vision, so this becomes more common in older people and can be equally common in men as well as women.

Using Colour Coding Safely

Although the proportion of employees who can be expected to have colour blindness is never likely to be more than 10 per cent, employers also need to be aware of their health and safety responsibility in terms of using colour codes and signs. At its most simple, this means not just using a red sign to indicate danger – someone with red-green colour blindness may just see it as muddy brown and ignore it.Safety signs and codes can be done in colour for the vast majority of employees, but backup systems using clear symbols (such as the electric shock danger symbol or the stop sign) and an explanation of the danger in words should be done wherever possible.

Continual Assessment

In employment situations where the ability to distinguish colour is critical from a safety point of view, testing before employment is obviously necessary but, as employees eyes can change with age, and exposure to disease or environmental factors, continual and regular testing is also a good idea. Annual testing is something that needs to be considered and that few employees will object to.