When can you diagnose colour blindness and how?

[beachyhead]

Ds (3) knows all his colours but draws a complete blank at blue and green. I know these are two of the indicator colours for colour blindness, but I don't know how to get him tested?

You could try this . If you click to see the actual poster and then click on the poster you get a bigger image. It will be dependant on how good your colour monitor is though!

Does your DS name blue & green incorrectly or does he sort itmes incorrectly if you as him to put all the same colours together? He is still quite young and could just be getting confused sometimes.

No he just looks at them blankly and asks me what colour it is. Knows all the browns, grey etc, but just these two....Thanks for the link.

I have noticed lots of men see blues and greens differently to me and wondered if it was a man thing. Have known four colour blind men (including my brother) but I'm not sure how early it was diagnosed. It's red and green they have trouble with though.

spacemonkey - i have noticed the same thing too!!!
also I have a beige bag - definitely beige - which dh is adamant is khaki green....

weird isn't it!

Colorblindness occurs in men, but it's carried on the x gene, so therefore is inherited from the mother. Does anyone on YOUR side of the family have colorblindness? My dh is colorblind. Unless the light is just right, he can't tell red from green...they both look grey to him. This also means that he sees purple as blue as he doesn't see the red component in it. However, he doesn't have a problem with blue. It doesn't sound like your son is colorblind if he doen't have a problem identifying red. In any case, it isn't fixable and doesn't really have major implications on their life, so I wouldn't worry about it.

They do an 'ishihara' (sp?) test where there are lots of coloured circles with a picture or number inside.

My maternal grandfather is colourblind and one of my brothers is also colourblind so I'm looking out for it in my 3 ds's as there is the possibility I carry it and could have passed it on (and also not of course!).

By the way, I think the term now is colour defective isn't it (but we don't hear of people making formal complaints if someone calls them colour 'blind' ).

Yes, and I wouldn't worry too much about it - there are certain careers you can't go into like armed forces and the police force but my brother is a graphic designer and gets along fine! He gets brown/red/green and purple/blue mixed up mainly.

'Toddler Taming' says that 'may get green & blue confused' somewhere and I think that's in the 3 yr old developmental bit, so maybe its normal? My DD always does (now 3). But they are quite close on the colour spectrum anyway aren't they - aquamarine, tourquoise, sea green etc.

Yes they are quite close anyway.

I can distinctly remember my little brother learning his colour and saying that our brown lounge curtains were red.

Thanks for the link SoupDragon - I might get ds1 to do this later. He usually gets blue and purple mixed up but he's still only 3.

Colour blindness, although does occur in some females, is much more common in males. It's passed on genetically (I think) from mothers to sons primarily.

Both my dad and FIL are colour blind, so are some of our male friends.

I still have problems with blue and green, and I'm sure I'm not colourblind. I often embarrass myself by thinking I can see police lights in my mirrors, pulling over and then realising its the green traffic lights I've just driven through I always put it down as just one of those things that went with having generally poor eyesight!

As SofiaAmes says it is passed on via the X chromosome. It's a recessive gene and so if you have a girl and therefore XX with colourblindness on one and not the other, it doesn't manifest (a gene that is recessive on the X chromosome would have to be present on both X chromosomes to be inherited). When you have a boy, and therefore XY it does.

I don't think I've explained that very well but anyway, it is much more common in boys! Hence my grandad is colourblind, my mother isn't but has passed it on to one brother and then it's always possible she's passed it on to me but I don't have it but could have passed it on to ds's.

Does that make sense?!!?

both my ds's are colourblind, the commonest form is red-green colourblindness, although my great grandmother had the rarer blue-yellow version. My father is colourblind and it has passed through me to them. As I bonus I get extra specially good colour vision!!

DS1 is very severely colour blind, we took him to be tested at Vision Express when he was 4, they have the dotty pictures with symbols instead of numbers for young children. Watching him screw his face up trying to see what was there was hilarious. He can only see bright blue and yellow clearly, everything else is sort of shades of murk.

DS2, 3, is obviously colourblind too, although we haven't bothered to get him tested. HE is less severely affected than his big brother.

We have loads of pointless arguments about the colour of various objects where everyone claims that they are the one who can see properly. DS1's favourite colour is pink although he can't see it!!

The test is free at any opticians, and we just dropped in at Vision express to ask about it and they did it on the spot. Approx. 1 in 8 men have some degree of colourblindness apparently.

1 in 8, that's a lot. Mind you, the lazy gene is far more prevalent isn't it?

my ds's definitely have the lazy gene

Mine too...it's from their father!!!