I read in popular science magazine that in some languages the colour blue is often represented by the same word that defines green, or darkness, in several languages. The suggestion was that some cultures haven't had a seperate concept of the colour blue. It is supposedly common amongst tropical people, where blue-yellow colour blindness is also sometimes more prevalent. There was also an experiment outlined which tested the effect of degradation of vision due to UV-B light, as a possible cause. Just seemed to me interesting anyway, and I was wondering if anyone had heard of this sort of 'cultural colour blindness' before.

Thats interesting, i don't know. Navajo has only one word for blue and green also, but they do have a segregation, blue blue is called blue of the sky, green is called blue of algae.

have i heard of River blindness? yes i have heard of that. but coloured blindness, sheesh, never heard of that. I seriously will want to know more about this Coloured blindness.