Jason Bradwell's 365/366 Photo a Day Blog

The dog's eye is more discerning of dim light than man's and is less able to sharply focus on detail; thus he sees better in the dark than we do but surrenders some visual acuity. It has long been thought that dogs do not discern color, but that supposition has been debunked by recent research. Current wisdom holds that dogs see some colors but do not have the detailed color vision of primates, including man.

Dog eyes are protected by upper and lower eyelids, by a third eyelid or haw, and by tears. The eyelids are lubricated by a thin layer of mucous to avoid irritating the surface of the cornea.