"Paul Corfield" wrote in message
...
On Tue, 2 Feb 2010 16:46:16 +0800, "DW downunder" noname wrote:

I think, Yokel, that there are more colour-blind (colour vision impaired,
or
colour-challenged) people around than southpaws (lefties, mollydookers).
You
can get a job in railway operations as a left-hander but not if you're
standard red-green "colour-blind". Haven't found a way around it, yet.

Well indeed. As a colour blind person I spectacularly failed the LT
colour blindness test but I this was not a surprise and I wasn't going
for an operational job. I have still driven trains though - albeit
under test conditions, not with passengers.

I
understand the incidence of colour vision impairment is around 25% of
males
and a low % of females, maybe 13% of the total population.

Those percentages look high to me. I don't know the numbers but the
instances of colour blindness in females is very, very low. I doubt the
overall proportion (of the population) is anywhere near 13%.

Likewise, it's
amazing how many maps are hard to read for this 13%, how many documents
use
nice red script over a beautiful verdant green tree background - even our
local RAC has managed that one.

While I can cope with the tube map without difficulty there are some
maps which are impossible to use because of poor colour choices or
excessive use of colour / cramming colours together. Complex schematic
bus maps where every route has a colour can be impossible to deal with.
I suspect the designers have no idea how unusable their end product is
for a small proportion of the population.

--
Paul C



Well, that's a fair percentage of the regulars at uk.r - already. It's
comforting in a way to know that I am not alone.

As to the numbers, I was going on data from a long time ago, and it could
have been 1:25 rather than 25% (we're not on gradient thread, are we -
checking - OK). So, sorry if my numbers were wrong.

Nonetheless, that's rather a high number. We seem to be getting similar
numbers for ADHD and autism, too. Mainly male-oriented. I wonder how much
overlap there is? Just idling thinking, really, as I'm ADHD, colour-blind
and flat-footed. That's why I don't play poker - genetically predisposed to
a lousy hand. G & bear it

DW downunder