Dre Morggan Debaets

 

By Dr Morggan Debaets, optometrist

Co-owner of Alliance Opto-Réseau clinics
of St-Félicien and Métabetchouan-Lac-à-la-Croix

Have you ever wondered how your dog or cat sees?  At Opto-Réseau, even though our patients are human, we sometimes get questions on pet vision.  So we’ve put together some information on the subject:

Dogs

Although a dog’s visual acuity (ability to distinguish details at a distance) is six times less than its owner’s, its field of vision is much wider because its eyes are positioned more to the side of the head than in humans. Like us, dogs have three-dimensional vision and can see colours (except red and orange). And because of the particular anatomy of their retinas, their nocturnal vision is much keener than ours. So dogs detect movement better than us, but are not as good at distinguishing details.

Cats

Cats don’t see as well as people either—especially up close! They see best at distances between 10 and 80 cm.  What’s more, they are essentially colour blind because all colours except blue and yellow look grey to them! Because of their highly reflective retina, however, cats do see better than us at night. They also detect slight movements very easily, even in the dark, which makes them excellent hunters.

Cats and dogs can develop cataracts, glaucoma, conjunctivitis, and corneal lesions, which a vet will treat in much the same way as in humans.

Birds

Birds have extremely good vision: some falcons can see an insect at distances of 2 millimetres to 18 metres! Birds can also see many more colours than humans. Although their field of vision is very wide, their eyes don’t move, so they have to turn their heads from side to side to see around them. Some birds can even turn their head more than 180°! The only downside? Their three dimensional vision is not as good as ours. 

As for other animals, we could generalize by saying that browsing animals have less visual acuity, but a nearly panoramic field of vision. Some animals see better at night than during the day. Insects can see ultraviolet rays, while rabbits have a 360° field of vision and can even see above themselves without moving their eyes! So it’s not easy to surprise a rabbit!