Colour Vision Deficiency

[DeanoNZL]

Hi all,
Just wondering how many people in IIS land suffer from it?
I can remember at school having to get the teachers to not use crimson chalk on a dark green blackboard. It was shimmering.
Traffic lights are ok.
Red navigation lights at night are tricky.
The 90m marker on a golf course(red), impossible!:lol:
And viewing subtle shades of red in Astrophotography is also tricky.

How have you been effected by it? Thoughts appreciated.

[Kevnool]

Sorry Adrian never came across it.....cheers Kev.

[GeoffW1]

Hi,

Well I am 80% red/green colourblind, the most common type (although that has sub-types as well).

It stopped me considering several careers when young, but has not had any serious effect apart from that, just minor aggravations.

I was glad to know I could not pass this hereditary condition to my sons, since it is only transmitted by the mother (however females are less likely to be colourblind).

I doubt that I could ever achieve great success in astro-photography since it seems to emphasise colour balance and image correction. I could be wrong though, that did happen once years ago :P. I might try it yet.

Cheers

[Terry B]

As part of my job I occasionally test peoples colour vision. I had a young lad come in once for assessment for a racing car license. I tested his vision and he was totally green colour blind. He had know idea that he had colour blindness. I asked him what his job was.
He told me he was a apprentice spray painter.:eyepop:

I suggested he get the colours checked before he sprayed anyones car.

[GrahamL]

Your wallets happy for the moment then Geoff :)

Are there different shades of colours that can get a little confused with this ? .. I know theres some family history with me but I see red amber green ok .. though I do recall a conversation with the wife once or twice ( she paints ) were a colour appears to me be very differant to how she sees it ?

[Ian Robinson]

No, I am lucky that my colour vision is fine.

Just find it hard to read fine stuff in bad light now a days (well I am 51).

[GeoffW1]

Hi,

Yes, that is true. For a start to the confusion, it is possible to be a little colourblind, say 10%, or a lot, like me. Complete 100% colourblindness is rare, and is often associated with other vision defects when that bad.

Actually colourblindness is a symptom, and can arise from many different causes, but sticking to the best understood cause, an inherited deficiency in one or more types of cone cells in the retina, it can be best described as an inability to distinguish subtle differences in hue.

For instance if there is a vivid green shrub at any distance, with a red flower on it, I will not be able to see the flower unless it is considerably lighter or darker than the surrounding leaves. However if I go up to the flower and put my face next to it, I will see it much as anyone else does, provided it is pure red.

If however the flower is violet or purple or some other mixture with red, I will not see it as others do.

There are 3 types of cone cells, short, medium and long wave, the sensitivity of which peaks for blue, green-yellow, and yellow-red light. If there is an inherited deficiency in one of these, there will be a reduced ability to discriminate colours around the peak for that cell. I lack the middle kind.

So yes, there are lots of different possibilities for a deficiency in colour vision. If you were interested to find out about any in yourself, you would need to be professionally assessed, but you can get a fair idea here

http://www.toledo-bend.com/colorblind/Ishihara.asp and here

http://colorvisiontesting.com/ishihara.htm#plate%20with%2010%20an swer

How's that for a rant ;) You pressed my button then.

Cheers

[GrahamL]

hmm ok . ..the bottom left .. 6 .. I think it is .. I have a lot of trouble making that out the rest are very clear .. The 2 and 5.. I can see both probably more 2 than 5...?


revisiting that without the prompting I see a 2 everytime at a glance .. weird ..
yellow green and red are always yellow green red to me ??

[xelasnave]

I am colour blind and it has a dramatic effect when trying to process...my images are usually green so everyone says I just cant notice it... red green..
Anyways not to worry I can still see pretty well detail wise and my images may look strange to others but I dont see it and they look ok..and as I am the only one I need please there is no need to let it get me down.
I did the test on the first site and it is a red green thing... still I see the traffic lights,
alex
alex

[AlexN]

Alex, You and me both...

I am color blind to some extent.. I mix up reds with pinks, reds with orange, orange with yellow, light blue with silvery metalic colors, dark blue with purple, light purple with pink, green with brown...

I think I should do away with the color camera and image with a mono camera in Ha.. :D Might be my best bet...

Strange thing is, I can usualy tell if two colors are the same, even if I cant tell you what said color is... Ie, when im processing my images, I can match the color in my image to a master image I acquire elsewhere.. (Usually either hubble visible light images or pics from the likes of Martin Pugh, Peter Ward, Rob Gendler etc... Those whos images surpass my wildest dreams..)

[firstlight]

I heard once that the traffic lights contain other colours: the red has orange, the green has blue, so as to allow most of the population tell what the light indicates.

Makes sense to me. I don't suffer from deficiency, but Rigil does. Apparently red/green deficiency is common to 10% boys.

[GeoffW1]

Hi,

Yes, the green GO light is an aqua with blue in it, since very rarely do people have deficient clour vision in all those wavelengths. It does not help to put orange with red.

The amber light is more of a problem I found, since I could not tell a very dirty amber light from a new bright red one.

However I could pass the driving test on the position of them.

For those interested here is a list of the intersections where you might encounter me in Sydney:

King Georges and Hillcrest
Boundary and Roberts
King Georges and Forest
Boundary and Forest

....more later ;)

Cheers