Newslink November

Towards your CPD: Colour blindness and driving
Pass it to the bloke in red...
Continued from page 21
If patients are troubled by colour blindness,
they can wear colour blind glasses to
compensate for the problem, which generally
will not affect their daily life.
Some rare retinal disorders associated
with colour deficiency could possibly be
modified with gene replacement techniques.
These treatments are under study and might
become available in the future.
Conclusion
Colour vision deficiency – also known as
colour blindness – is a condition which limits
a person’s ability to recognise and
differentiate between different colours. It
does not stop you from driving, and most of
the estimated three million sufferers in the
UK will also hold driving licences.
But because so much of driving is linked to
coloured signs, drivers who are colour blind
need to take extra precautions. They have to
respond differently to the colour sequence of
traffic lights, for instance, and not rely on a
burst of amber and then green light to know
it’s time to go.
Rather, their signal to move off if safe to do
so is more understated and possibly harder
to spot.
When we teach pupils to understand traffic
signs we get them used to the different
shapes of the signs, and what they mean. We
say, for instance, that road signs in the shape
of an equilateral triangle are designed to warn
you about the road layout or any hazards that
lie ahead, such as sharp bends.
But note that they almost always have a
red border; if your pupil struggles to see red,
then that crucial piece of evidence as to what
this sign is saying is lost to them.
Similarly, circular road signs give orders
which must be followed. But those warning
circles are always encased in red, too.
Remember too that we teach pupils that
blue circles usually give a positive instruction,
such as ‘turn left ahead’. Again, if a pupil can’t
Team sport administrators have often been
criticised for not taking into account the
difficulties colour blind fans have in following
the action when teams play in clashing kits
- as far as colour blind people are concerned.
The photo far left shows two players from
the Switzerland v Cameroon match at the
Qatar World Cup in 2022; the photo to its
right shows how the players looked to
someone who struggles to differentiate
between red and green.
The Football Association in England have
tried to counter this by launching a campaign
to encourage teams to be more aware of the
difficulties that kits in some colours can
create. Above, the photo left is of modern
kits, with their ‘colour blind alternatives’ to
the right
pick out the colour blue, a bit of your
guidance is lost on them.
In short, there’s nothing to say you can’t
drive while colour blind, but there is a chance
you may struggle in some scenarios if you
are not careful.
Possibly a bigger problem comes when
driving at night, when there is a link between
a driver’s colour blindness and their lack of
depth perception, which is important in
calculating distances.
THE COLOUR VISION STANDARD
A colour vision standard was introduced in Britain for bus drivers in
the 1930s soon after traffic lights came into use, but was abandoned
after Norman’s investigation was published in 1960. Various
European countries have or have had colour vision standards for
drivers of motor vehicles but the EU, in its endeavours to set up a
Europe-wide driver’s licence, seems to have no plans to introduce
one or even an inclination to discuss it.
However, 40 US States have a colour vision requirement, as does
the US Federal Motor Carrier Safety Administration (FMCSA), the
body that regulates interstate commercial motor transport.
It requires its medical examiners to state whether the applicant has
the ‘ability to recognise the colours of traffic signals and devices
showing standard red, green, and amber’ but does not seem to have
a defined test procedure to assess this.
There is doubt whether the FMCSA ‘standard’ for colour vision of
drivers in the US is effective: its handbook for medical assessors
observes that ‘true color perception deficiencies are rarely
disqualifying’.
24 NEWSLINK n NOVEMBER 2023