USA : Saturday, 15 January 2011 (Local Time)
Most people think that dogs see in black and white, and shades of gray. The truth is that dogs see in color, but not well.
Jay Neitz at the University of California, Santa Barbara, tested the color vision of dogs and confirmed that dogs actually do see color. Dogs see less colors than humans. A dog's eyes have fewer light catching cells called cones that respond to color than humans. Humans see a rainbow as violet, blue, blue-green, green, yellow, orange and red. Dogs see a rainbow as dark blue, light blue, gray, light yellow, darker yellow (sort of brown), and very dark gray. A dog sees the world in yellow, blue and gray.
It is amusing to consider that many dog toys are colored red or bright orange. Since red is difficult for dogs to see, it likely appears to the dog as a very dark brownish gray - maybe even black. A bright red toy may be super-visible to you, but your dog may find it difficult to see.
The diagram on Psychology Today shows the differences between how dogs and humans see the visible light spectrum.
For many test trials, dogs were shown three light panels in a row--two of the panels were the same color, while the third was different. The dogs' task was to find the one that was different and to press that panel. If the dog was correct, he was rewarded with a treat that the computer delivered to the cup below that panel.
Neitz confirmed that dogs actually do see color, but many fewer colors than normal humans do. Instead of seeing the rainbow as violet, blue, blue-green, green, yellow, orange and red, dogs would see it as dark blue, light blue, gray, light yellow, darker yellow (sort of brown), and very dark gray. In other words, dogs see the colors of the world as basically yellow, blue and gray. They see the colors green, yellow and orange as yellowish, and they see violet and blue as blue. Blue-green is seen as a gray.
One amusing or odd fact is that the most popular colors for dog toys today are red or safety orange (the bright orange red on traffic cones or safety vests). However red is difficult for dogs to see. It may appear as a very dark brownish gray or perhaps even a black. This means that that bright red dog toy that is so visible to you may often be difficult for your dog to see. That means that when your own pet version of Lassie runs right past the toy that you tossed she may not be stubborn or stupid. It may be your fault for choosing a toy with a color that is hard to discriminate from the green grass of your lawn.
Story and Foto from : www.northeastcobb.patch.com and www.psychologytoday.com
