Our 4-legged friends boast great hearing and they probably see better than us too, right? Not exactly. The anatomy of the canine eye is different from that of a human, so color perception can vary greatly. The same goes for peripheral vision and the ability to orient in the dark, among other things. So how do dogs see?
Anatomy of the Canine Eye
To get an idea of how dogs see, you must first examine the structure of their eyes. In fact, the anatomy of your beloved pet dog’s eye is very similar to the human eye. For example, dogs have upper and lower eyelids, just like humans. There are many other anatomical characteristics shared by the two species, including:
- the sclera: this is the fibrous membrane called the “white of the eye”
- the cornea: the thin, transparent layer at the front of the eye that is relatively fragile
- the conjunctiva: this is the inner lining of the eyelids that becomes pink and inflamed when there are allergies or eye infections.
- the iris: the colored part of the eye that contains smooth muscle and controls the size of the pupil, thereby regulating the amount of light entering the eye
- the pupil: this is the black point in the center of the iris that contracts in bright light and dilates in darkness
- the lens: located behind the iris, it changes shape to focus light on the retina
- the retina: it is located behind the eye and has two types of photoreceptors (rod cells), one of which detects light and movement and the other detects color.
Same eyes, but different
However, understanding how dogs see also requires attention to eye structures that humans lack. Those parts are:
- the light carpet (tapetum lucidum): located behind the retina, the tapetum lucidum is a light-reflecting layer, which increases the light available to the photoreceptors. Its presence is the reason why the animal’s eyes appear to glow in the night light.
- the third eyelid: known as the nictitating membrane, the third eyelid is transparent or white 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?
Generally, a dog’s iris, or the colored part of the eye, can be brown, blue, gold, or hazel, with brown being the most common color. Like humans, dogs can have non-matching eyes, that is, different colors. Heterochromia usually occurs in dogs with a merle coat or in certain breeds such as Huskies or Australian Shepherds. This little precision in the past, let’s see how do dogs see exactly?
Do dogs see better than people?
Many people wonder how dogs see compared to humans. Do they have better vision than ours? However, there is no simple answer, because dogs have more limited vision in some areas, but better in others. Some of the things to look at are peripheral vision, motion detection, visual field width, color perception, and dark vision.
Surprisingly, this is also a question of dog breed. For example, most Labrador Retrievers have the best eyesight among their peers, so they are often used as service dogs for the visually impaired. In addition, different races cover 250 to 285 ° of the visual field against the mediocre 180 ° for humans. And how do dogs see at a distance?
At the same time, the dog’s vision is far from perfect. If a dog is a person, it is considered nearsighted and needs glasses to see more distant objects, such as a classroom blackboard or a street sign. If a person can see something 23 meters away, we have to put it 6 meters away from a dog so that this one can see it in the same way!
In contrast, dogs have more rod cells in the retina than humans. These receptors are sensitive to motion and low light. This explains why dogs can see moving objects better than stationary objects and why they can be trained even without speaking, using only hand gestures. In fact, dogs are 10 to 20 times more sensitive to motion than humans!
“Can dogs see in the dark? is another fairly popular question. Yes, and they have many anatomical advantages that allow them to see better in the dark than us. Besides the rods already mentioned, their large pupils allow more light to enter the eye and their lens arranged closer to the retina brightens the image. The presence of light carpet is another characteristic that determines the best night vision of dogs.
Do dogs see colors?
Finally, the million dollar question: can dogs see color? Yes, but only in blue and yellow colors. 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 dog’s color spectrum. Did you know that hunters can wear an orange vest to stay visible to other hunters, but not be noticed by animals? Humans have what is called trichromatic vision, which means we can see more colors than dogs. Now you know how to see dogs!
Source used: www.petmd.com