From: ldo@nz.invalid   
      
   On Sun, 22 Feb 2026 03:31:03 -0000 (UTC), quadi wrote:   
      
   > Also, it might be relevant to mention that there are women who walk   
   > among us who see a whole different and vaster universe of color than   
   > everyone else. That's because the genes for the pigments in the   
   > cones of the eye are on the X chromosome, so a woman one of whose   
   > parents is an anomalous trichromat (a kind of color blindness) could   
   > have the three normal cone pigments plus the anomalous pigment in a   
   > fourth kind of cone.   
      
   I have heard about such. One such tetrachromat woman had a successful   
   career as an interior decorator. Apparently her talent was in   
   distinguishing extra shades of ... beige.   
      
   Conversely, I have heard of cases of colour-blindness being cured by   
   the wearing of specially-designed glasses. I suspect the sufferers   
   were not true dichromats, it was just their misfortune to have colour   
   receptors with peak sensitivities too close together in the spectrum.   
   So I think the special glasses were basically filters to magnify the   
   difference in stimulation between those different receptors.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)