A dog’s vision is not the same as our own. Do they perceive colors? Can they see in the dark? There are lots of different theories out there on the subject of doggy vision.
Contrary to preconceived notions, dogs can perceive colors, even if their spectrum is narrower than ours. We tend to say that the dog is dichromatic, because his retina contains two types of cones that enable him to see shades of yellow and blue. However, he poorly distinguishes between red and orange. Hues appear clearer and more pastel to him, and images are less detailed.
A larger field of vision than our own
Our field of vision can cover up to 180°. A dog’s field of vision, however, can go up to 287°. This means that our dog sees better on the side periphery and detects movements more easily.
However, his binocular vision (the field of vision perceived by both eyes at once) is reduced. It’s this visionthat enables one to see in three dimensions; thus, a dog’s ability to see three-dimensional images is more limited compared to a human’s.
Finally, his capacity to distinguish between two very close points (visual acuity) is six times weaker than that of a human, which means that he makes out details poorly when objects are more than one foot (30 cm) away. If you call your dog from far away while standing still, your dog will have a hard time recognizing you. He must then use his olfactory ability.
Thanks to a thin reflective film that covers their retina and acts as a mirror, a dog has very good vision in the dark (about five times better than that of humans). This ability makes him a good hunter at night, as long as the moon and stars light his path a little.