My daughter-in-law insists that her optician said that my grand-daughter is colour blind. I find this difficult to believe because since she was small enough to draw - she is seven now - she has had absolutely no trouble in identifying colours of every variety from a very large box of mixed felt pens and coloured pencils when she is staying with me! What can she be talking about please?
It is unusual for a girl to be colour deficient. In boys the incidence is about ten per cent of the population, in girls it is about 0.5 per cent. Girls tend to have a more subtle less obvious form or colour deficiency, so in your grand-daughter it may only be slight, but colour vision tests can reveal the problem. You should do the Ishihara test online with your daughter. Bear in mind that this won't be very accurate because every computer screen portrays colours differently. You may be surprised! The link is below: