Why Do Dogs See Only in Black & White?

It is a common misconception that dogs cannot see color. In fact, in recent studies scientists have discovered that dogs are able to see much clearer, and with color, than what was believed.

  1. Cones

    • Cones are photoreceptor cells in the retina of the eye that function best with bright light. Dogs have two cones, while humans have three different cone types. Each cone contains a photopigment that is maximally sensitive to separate wavelength of light. These wavelengths make color possible. Compared to humans, the canine cones are not as nearly maximally sensitive.

    Color of Sight

    • Dogs are able to see color in a very limited spectrum. Dogs are able to see blue, but green, red and yellow all appear similar.

    Rods

    • The retina of the eye is lined with rods and cones in humans and dogs. Rods are able to work best in low light and are used for motion detection. Canines have more rods in the eyes than humans, which explains why they can be see better at night than humans.

    Peripheral Vision

    • The position of eyes is important and demonstrates the amount of the visual field that can be seen simultaneously with both eyes. Dogs' eyes are placed on the sides of their heads, thus their visual field is 240 degrees. Along with the position, binocular vision is necessary for judgement of distances. Their central binocular field of vision is approximately half of humans.

    Acuity

    • Acuity is the ability to see detail. Dogs see less detail that humans do. human. Acuity can be measured in cycles per degree. A way of measurement is to see how many lines can be seen as distinct entities in a visual field. Humans are able to see 30 cycles per degree while dogs can see about 12.