Pugs, for example, have a small spot of sharp vision - an “area centralis” - as humans do. The shorter a breed’s head, the narrower (more circular) the streak tends to be. In dogs with long heads like wolves, the streak is wide, with the nerves evenly distributed. The visual streak varies greatly among breeds, and studies suggest that different breeds see the world differently.

The visual streak is a horizontal band in the retina right above the optic nerve this area has the highest concentration of rods and cones, and vision is sharpest here. It’s also what allows them to see in dimmer light. And unlike humans, dogs have a reflective lining behind the retina called the tapetum lucidum it’s what makes dogs’ eyes glow eerily when light hits them. Canine eyes are different than human eyes in that they have a third eyelid called the nictitating membrane, a thin whitish-pink tissue that protects the eye. Dog eyes also contain structures not found in a camera, such as the gel-like vitreous humor that fills the eyeball and gives it shape. As a result, dogs don’t see as many colors as do people.

The cones and rods send these signals via the optic nerve to the brain, which constructs an image from them.ĭogs Get Dry Eye Too.Some Breeds More Than OthersĮyes without tears are only for Cameron Diaz in The Holiday.ĭogs have only two types of cones, compared with the three types in human eyes. Light then passes through the cornea and lens, which focus the light on the retina, a layer containing color-sensitive cones and motion- and light-sensitive rods, which convert light into electrical signals. Light enters through the pupil, and the iris controls the amount of light allowed in. To understand eye problems in dogs, it helps to know a little bit about how their eyes function. “Now that I specialize in ophthalmology, I more often see cataracts, glaucoma and retinal disorders.” How Dogs’ Eyes Work Christine Lim, DVM, DACVO, a veterinarian in Chicago. “As a general practitioner, I was often presented with problems such as conjunctivitis, dry eye and corneal ulcer,” says Dr. Some eye disorders occur more often than others (a dog’s breed usually plays a role). If your dog’s eyes have been looking a little red or cloudy lately, or if you’ve noticed they’re pawing at, rubbing, or showing signs of irritation around their eyes, you might need to make an appointment with your vet.Įye problems in dogs are no joke - dogs can suffer from a host of health conditions including glaucoma, conjunctivitis, dry eyes, cataracts and more. It could be something more than cuteness, though.

They are the epitome of the “pleading face” emoji. It’s been proven that gazing into your pet’s eyes produces oxytocin and promotes bonding. “Puppy dog eyes” gets dog parents every time. See our privacy statement to find out how we collect and use your data, to contact us with privacy questions or to exercise your personal data rights.

Dog one eye dilated