Are Dogs Color Blind?
For decades, people believed that all dogs were colorblind. But recent research has dispelled this misconception and demonstrated that dogs can perceive the full range of hues.
Dogs’ limited color vision has enabled them to adapt well in dim light and detect subtle movements. Their eyes have evolved for nocturnal hunting, featuring larger lenses and corneal surfaces that can pick out small details in dim lighting conditions.
Your dog’s eye has a retina composed of cones and rods, as well as ganglion cells that regulate their circadian rhythms. These are essential for your pup’s sense of time as they help them stay alert throughout the day.
However, these two cell types don’t function together the same way they do in humans. Humans possess three types of cones which are sensitive to different wavelengths of light and can transmit signals for all hues on the color wheel.
Dogs only possess two kinds of cones, which cannot transmit signals for red or green. This condition is known as a yellow-blue dichromatic vision – similar to human color blindness.
Though dogs lack cones that enable us to see red and green, their eyes still possess an array of color receptors that enable them to distinguish different shades of blue and yellow. As a result, your pup’s vision may not be quite as vibrant as that of humans.
You might be wondering why your pup prefers playing with a yellow tennis ball rather than the green one you bought him. He likely can’t see all the subtleties in colors as you do, so he won’t know which is best suited for him to use.
According to a study published in the Journal of Neuroscience, dogs’ cones do not have the capacity to detect red or green light, instead they only detect blue, yellow, and a combination of those colors.
Researchers also observed that when dogs were asked to identify two pieces of paper with differing hues, they were able to differentiate between them. Researchers placed a light and dark yellow piece of paper on a feed box and asked the dogs which one had the lighter shade.
Another experiment revealed that dogs were able to identify dark red paper painted with white paint. Through training the animals, the scientists taught them that this darker paper meant they should pick it up for a treat – thus teaching them which item to pick up.
Yes, your dog does perceive a great deal of yellow, blue, and grayish-brown shades. However, they rarely detect red or green tones, while only certain shades of blue and yellow can be distinguished.