Dogs do not have true night vision, although they can see in the dark. When there is no light at all, neither you nor your dog will be able to see anything.
On the other hand, even in the “dark,” there are usually still some sources of light present, such as the moon, streetlights, or even the LED of your standby TV. It’s easy to dismiss them as insufficient at first, but once your eyes adjust to the dim light, you’ll be surprised by how much you can make out.
Dogs’ eyes have adapted over time to function optimally even in low light, allowing them to detect movement and identify things despite the poor illumination. But if there is no illumination at all, your dog will be blind.
The structure and function of a dog’s eye are not dissimilar to that of a human’s.
When you or your dog are out and about in the world, light enters your eye through the cornea and the crystalline lens at the front, before passing through the pupil and into the retina. The amount of light entering the eye is regulated by the pupil, which may either widen or contract. Your dog’s bigger pupil is the first of their remarkable adaptations that helps them see in the dark.
When light enters the eye, it is received by the retina, which contains specialised photoreceptors. In the retina, photoreceptors convert this light into electrical signals that are then sent to the brain, where they are decoded into images.
Both canine and human eyes include two distinct types of receptors. You may know these as rods or cones. Light and motion are detected by rods, whereas colour is seen by cones.
The difference in the number of cones between a dog’s and a human’s eyes explains why canines have a more limited colour vision. In contrast, dogs’ eyes contain much more rods than ours do, allowing them to detect significantly more light than we do.
But that’s not all; your dog also has another secret weapon that will help him see better at night.
Do your dog’s eyes sometimes glow green or red like a hellhound’s? They aren’t hiding monsters, though; they merely have reflective eyeballs.
The term “tapetum lucidum” refers to the layer of tissue located behind the retina in canines. Like a mirror, this unique tissue reflects light onto the retina, where it is needed. This offers your dog a second opportunity to make use of the light entering its eyes, increasing the quantity of light that its photoreceptors can absorb.
Thus, in the dark or in photographs, your dog’s eyes appear to shine because they are actually reflecting light back out.
Dogs don’t have the ability to see in the dark since they need to have some light to see.
Even while night vision goggles allow people to see in the dark, the way a dog sees in the dark is very different, as infrared light is not picked up by these devices. To see in the dark, your dog needs visible light even though it cannot perceive infrared.
However, dogs’ eyes have evolved in such a way that they require significantly less light in order to see than human eyes. Consequently, it may appear to us that they have night vision, when in fact they are only making use of light that is invisible to us.
Most of the animals we know are either nocturnal, or active at night, or diurnal, or active during the day. This isn’t always the case, though.
Crepuscular animals like wild canines are more active before sunrise or after sunset. There is considerably less light during these periods; nonetheless, it is not completely dark.
Because animals like deer are most active in the early morning and late evening, dogs and other canines have adapted to have excellent vision at these times. When combined with their heightened senses of smell and hearing, their ability to see in low light and detect movement made it much easier for them to seek for food.
Our canine companions have evolved to being active during the day with their human families, but their innate ability to see in the dark means that they can still go on nighttime hunts if necessary. Dogs can see clearly in daylight and brighter light, so the transition to a human schedule hasn’t seemed to trouble them too much.
While we can only guess at a dog’s night vision, we know it’s pretty good. They have much better night vision than humans.
You and your dog need some light in order to see, as neither of you can see in total darkness.
On the other hand, dogs have superior night vision compared to humans. The amount of light our dogs need to see clearly is about one-fifth of what we require, giving them a distinct advantage in low-light situations.
Your dog’s eyes are better able to make the most of dim lighting, which is why they are more effective at spying at night. Because their retinas include more rods, they can detect subtle changes in illumination with greater precision. Additionally, they allow in more light because their pupils are larger than ours. And now, at long last, they have that marvellous tapetum lucidum to bounce light around and use it again and again. There is no tapetum lucidum in the human brain. (Our blood vessels instead reflect the flash, making our eyes appear red.)
As a result of these clever adaptations, your dog has much superior night vision than you do. Your dog can now stroll around the living room at night without fear of banging its shins on the coffee table.
It’s possible that your dog knows its way around the house better at night than you do, but our moggies have greater night vision than our mutts.
The exact difference between a cat’s and a dog’s night vision is unknown, although current estimates place a cat’s night vision at being 1/6th that of a human’s, while a dog’s is 1/5th. Cats are slightly more advantageous than dogs, then.
Crepuscular animals, including cats, exhibit many of the same specialised adaptations to vision in the dark as do dogs. Included in this category are reflective cat’s eyes, which served as the model for the similarly named traffic safety product.
