Our 4-legged friends boast excellent hearing, and they probably see better than us too, right? Not exactly. The anatomy of the dog’s eye differs from that of humans, and therefore color perception changes dramatically. The same applies to, among other things, peripheral vision and the ability to orient oneself in the dark. So how do dogs see?
Canine Eye Anatomy
To get an idea of how dogs see, you must first examine the structure of their eyes. In fact, the anatomy of your beloved dog’s eye is very similar to the human eye. For example, dogs have an upper and a lower eyelid, just like humans. There are plenty of other anatomical features that the two species share, including:
- sclera: this is the fibrous membrane called “the white of the eye”
- cornea: the thin, transparent layer at the front of the eye, which is quite fragile
- the conjunctiva: this is the lining inside the eyelids, which can become pink and inflamed when suffering from allergies or an eye infection
- iris: the colored part of the eye that contains the smooth muscles and controls the size of the pupil, thus regulating the amount of light entering the eye
- the pupil: this is the black dot in the center of the iris, which contracts in bright light and dilates in darkness
- the lens: located behind the iris changes its shape to focus light on the retina
- the retina: it is located at the back of the eye and contains two types of photoreceptors (rod cells), one of which detects light and movement, and the other detects color.
Similar eyes, yet different
But understanding how dogs see also requires attention to eye structures that humans lack. Such features are:
- the light carpet (tapetum lucidum): located behind the retina, the tapetum lucidum is a layer that reflects light, increasing the light available to the photoreceptors. Its presence is the reason why an animal’s eyes are seen to glow in the light at night.
- the third eyelid: known as the nictitating membrane, the third eyelid is transparent or whitish and is located in the inner corner of the eye near the nose. Its main function is to protect the eye and moisturize it.
What eye colors can a dog have?
In general, the dog’s iris, or the colored part of the eye, can be brown, blue, golden or hazel, with brown being the most common color. Like humans, dogs can have mismatched eyes, that is, different colors. Heterochromia occurs most often in dogs with merle coats or in certain breeds such as Huskies or Australian Shepherds. This little precision in the past, let’s see how dogs see accurately?
Do dogs see better than humans?
Many people wonder how dogs see compared to humans. Is their vision better than ours? However, there is no simple answer, as dogs have more limited vision in some respects, but better in others. Some of the things to look at are peripheral vision, motion detection, visual field width, color perception, and dark vision.
Oddly enough, it’s also a matter of dog breed. For example, most Labrador retrievers have the best eyesight among their peers, which is why they are most often used as service dogs for the visually impaired. In addition, the various races cover 250 to 285° of field of view, against the mediocre 180° for humans. And how do dogs see in relation to distance?
At the same time, a dog’s vision is far from perfect. If a dog were a human, it would be considered nearsighted and would need glasses to see more distant objects, such as the classroom blackboard or a street sign. If a human can see an object 23 meters away, we should place it 6 meters away from a dog so it can see it the same way!
By contrast, dogs have more rod cells in the retina than humans. These receptors are sensitive to movement and dim light. This explains why dogs can see moving objects much better than stationary objects and why they can be trained even without speaking using only hand gestures. In fact, dogs have 10 to 20 times greater motion sensitivity than humans!
“Can dogs see in the dark? is another fairly popular question. Yes, and they have several anatomical advantages that allow them to see better in the dark than us. Apart from the rods already mentioned, their larger pupils allow more light to penetrate into the eye, and their lens located closer to the retina makes the image brighter.The presence of a bright blanket is another characteristic that determines the best night vision for dogs.
Can dogs see colors?
Finally, the million dollar question: can dogs see color? Yes, but only in blue and yellow shades. Because dogs can only see two colors, they have dichromatic vision. They can also see shades of gray, but colors like red, orange and green are not part of the color spectrum that a dog can see. Did you know that this is why hunters can wear an orange vest to remain visible to other hunters but unnoticed by animals? Humans have what is called trichromatic vision, which means we can see a lot more colors than dogs. Now you know how dogs see!
Used source: www.petmd.com