Re: Are dogs colorblind and why?

Faith,
  Dogs aren't colorblind, but they do see colors 
differently than we do.  Dogs don't seem to be 
able to see reds and greens very well, so their 
world probably seems to be in shades of yellow 
and blue.  For a comparison of how you and a 
dog see colors, go to this web site:
 
http://www.uwsp.edu/acad/psych/dog/dvision.htm 

Press the link for "Dr. Ps training site", then 
"General Topics", then "Vision".  The first 
article on acuity and color vision has the picture 
you should look at, so you'll see what I'm talking 
about. 

  Dogs don't see fine details as well as humans, 
either.  We usually see 20/20 or a little better, 
but dogs see about 20/80.  That's four times 
blurrier!  Dogs do see better at night, though, 
and they also see moving things better than we 
do.  That may explain why your dog can spot 
the moving ball that you throw in the woods.  He 
can tell exactly where it stopped moving.  This 
would come in handy for a dog in the wild 
hunting squirrels and other small stuff.  He'd be 
able to tell where the squirrel was going, and if it 
stopped, he could figure out exactly where.  I 
found some pictures of dog retinas too.  The 
retina is the back part of your eye that does the 
seeing for your eye.  There's one picture of a 
normal eye, and three pictures of dog eyes with a 
disease called progressive retinal atrophy.  
 
http://www.sheepdog.com/diseases/pra/pra.html

  I hope this helps to answer your question!

Tom