[ SHOWGSD-L ] COLOR VISION IN CANINES

From: "Doc Zoe" <wynsum@xxxxxxx>
To: showgsd-l@xxxxxxxxxxxxx
Date: Wed, 21 Mar 2007 20:15:05 -0500
A number of studies have been done to investigate the color vision of dogs, and 
the results have 
been conflicting. However, more recent, better controlled studies indicate that 
dogs do possess 
and use color vision, but not to the same degree that humans do. The 
photoreceptor used for 
color vision is the cone, and there are cones present in the canine retina. 
However, they are 
present in low numbers, comprising less than 10% of the total photoreceptor 
population in the 
central area of the retina, as opposed to the human retina which consists of 
nearly 100% cones 
in the fovea. Two distinct type of cones appear to be present in the canine 
retina. One type is 
maximally sensitive to light in the wavelength that appears violet to people, 
and the other type is 
maximally sensitive to light in the wavelength that appears yellow-green to 
people. Thus, it 
appears that the visual spectrum of color in dogs is divided into two hues; one 
in the violet and 
blue-violet range, probably appearing as blue, and the other in the 
greenish-yellow, yellow, and 
red range, which is probably seen as yellow. Light that appears blue-green to 
people probably 
appears as white or shades of gray to dogs. Dogs are unable to differentiate 
colors that appear 
as green, yellow-green, orange or red to people, and are unable to 
differentiate greenish-blue 
from gray. This is similar to people who are red-green color blind. However, 
one study indicates 
that dogs are better able to differentiate between subtle shades of gray than 
people, which would 
be advantageous in increasing visual discrimination in low light conditions, 
where insufficient 
light is available to stimulate cones.


============================================================================
POST is Copyrighted 2007.  All material remains the property of the original 
author and of GSD Communication, Inc. NO REPRODUCTIONS or FORWARDS of any kind 
are permitted without prior permission of the original author  AND of the 
Showgsd-l Management. ALL RIGHTS RESERVED. 

ALL PERSONS ARE ON NOTICE THAT THE FORWARDING, REPRODUCTION OR USE IN ANY 
MANNER OF ANY MATERIAL WHICH APPEARS ON SHOWGSD-L WITHOUT THE EXPRESS 
PERMISSION OF ALL PARTIES TO THE POST AND THE LIST MANAGEMENT IS EXPRESSLY 
FORBIDDEN, AND IS A VIOLATION OF LAW. VIOLATORS OF THIS PROHIBITION WILL BE 
PROSECUTED. 

For assistance, please contact the List Management at admin@xxxxxxxxxxxx

VISIT OUR WEBSITE - www.showgsd.org
============================================================================
[ SHOWGSD-L ] COLOR VISION IN CANINES

Other related posts:
