A Dog’s Eyes

Did you know?

  • Dogs are predators so their eyes face forward.  Animals that are preyed upon tend to have eyes on the side of their face to give them a wider view of the world so they can keep an eye out for danger.  However dogs’ eyes are placed more to the side of their heads than humans, giving them a more panoramic view of the world than us.
  • Dogs don’t need eyebrows in the same way as humans do to stop sweat getting into their eyes, as dogs only sweat from the pads of their feet.  Where dogs have markings that look like eyebrows, the markings can facilitate communication as the markings accentuate the movement of the eyes.
  • Dogs find direct eye contact threatening – don’t stare at a dog.
  • A plasma TV refreshes at a rate of 60Hz, in other words the screen is refreshed 60 times per second.  Since this is above a human’s flicker resolution ability of 55Hz, the image seems continuous and the gives us the illusion of continuity.  Because dogs can resolve flickers at 75Hz, the TV probably appears to be rapidly flickering to dogs.  This may explain why most dogs do not watch the TV, much less recognise objects on the screen.
  • Dogs’ eyes have fewer cones than humans, which means that they don’t have the full range of colour vision that we do.
  • The pupil in a dog’s eye is larger than humans, which lets in more light, but results in a loss of depth of field.
  • Dogs have a much higher proportion of rods in their eyes than we do, which gives them better visibility in low light.
  • Dogs’ eyes can produce tears, but dogs don’t weep.
  • Dogs seem to have eyes that are particularly sensitive to changes in their environment and have excellent motion perception, which is particularly useful to herding breeds and sighthounds.

Photo by Jose Rocha from Rio de Janeiro, Brasil – Flickr, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=3493364