Daylight Dog Vision
Sunday, February 06, 2011
In daylight, dogs see the world differently than humans. They are not able to see the world as clearly as we do, and their range of color perception is limited.
Clarity: A dog's visual acuity is approximately 20/75 (visual acuity is the ability of the eye to distinguish fine detail such as leaves on a tree or letters on a sign). So, if a dog with normal vision is just barely able to discern an object from a distance of 20 feet, its human counterpart is able to see that same object from a distance of 75 feet.
Color: A dog's eyes only have 20% of the color receptors (cones) that human eyes have. Dogs are dichromatic, meaning that they are able to only distinguish two primary colors – yellow and blue and combinations of the two. Human vision is trichromatic. People with normal color vision are able to discern three primary colors – red, green, and blue.
A normal dog's night vision is superior to that of humans. Dogs perceive motion better than humans too. I'll be addressing these and many more aspects of dog vision in the future.
2 Responses to Daylight Dog Vision
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Interesting… but if their visual acuity is that much less, how can they catch or run down balls when thrown a long distance, like with those ball launchers…?
Dogs have a keener ability than humans to perceive motion. Simply put, they process visual information at a much higher frame-rate than we do. Dogs also enjoy a highly evolved number sense. Their brains are hardwired to use “trigonometry” to calculate the distance, path, and speed required to capture a moving target, such as prey or a ball.