Parents often observe when they come home late at night their dogs walking or showing movement as if they are able to see at night; it compels them to think about whether dogs have the ability to see in the darkness or not. If they believe that dogs can see at night, another question that baffles the majority of owners is how clearly, they can see in the darkness, and in dim light or complete darkness. 

 

Are dogs able to see at night? 

Yes, dogs are able to see at night; they can see clearly under low light or dim light, and in the darkness, they can also see to a great extent. Due to their eye structure and the presence of more photoreceptors, they can navigate in the darkness. 

 

Parameters of dog eye vision: 

Dog eyes work just like human eyes, but there are some differences. Dog eye vision can be evaluated by the factors mentioned below: 

Visual acuity: it means sharpness of vision.

Depth of perception: how they can see and perceive critically.

Visual field: objects within this area can be seen.

 

Difference between dog and human's vision: 

Dog eyes are similar to human eyes with respect to morphology, anatomic structure, light reception, and interpretation of vision. Both human and dog eyes have a cornea, the outermost part of the eye that focuses light on the lens; this part is responsible for directing the light rays. Dog eyes, just like human eyes, have an iris and pupils, which control the amount of light reaching the light-sensitive parts of the eye. 

Dogs also have cones and rods similar to humans, but the main difference is in number; dogs have more rods than humans; on the other hand, humans have more cones than rods. This is the reason why dogs are able to see at night as compared to humans.

 

Trichromatic versus dichromatic vision: 

Humans have three cones that make us see red, green, and blue colors; this is known as trichromatic vision. On the other hand, dog eyes have two cones, so they are able to see two colors; this is termed dichromatic vision. This is also known as color blindness because of misreading cones for one color.

 

Difference between the visual acuity of dogs and humans: 

Visual acuity refers to your ability to see or discern details. Dogs have lesser visual acuity as compared to humans with 20/75 vision, which means that dogs can see details 20 feet away, whereas humans are able to see at 75 feet away. Human eyes have 20/20 vision with good and higher visual acuity.

Human eye	Dog eye
Humans have trichromatic vision due to the presence of three cones.	Dogs have dichromatic vision due to the presence of two cones.
They are able to see details more accurately.	They can't see details as accurate as humans.
Can see better in full light	Can see in full as well as dim light
They are able to see distant objects clearly.	Closer objects can be seen clearly.
Have a narrower field of vision because the eye is present on the head.	Have a larger field of vision according to the position of the eye.
Pupil size is small.	Larger pupil size

 

 

Structures that favor a dog's night vision: 

Dogs have anatomic structures, which make them see better at night in comparison to humans. Dogs have some advantages over humans in terms of eye morphology. 

 

Reflective tissue membrane (Tapetum lucidum): 

The thin membrane present behind the retina found in mammals reflects light on the retina by acting as a mirror; this enables them to see under low or dim light. Contrary to dog eyes, human eyes don't have this membrane, which is one reason that dogs are able to see better than humans at night.

 

Greater number of rods in the retina: 

Most mammals, including dogs, have more rod cells in the retina than cones, which are sensitive during dim light. Rods make them see and detect objects in the dark. Nocturnal vision in most of the hunting animals is due to the presence of a greater number of rods. 

 

Pupil size: 

Pupil size has a lot to do with the amount of light reaching the retina; a larger pupil allows more light as compared to a smaller one. Pupil dilation and constriction regulate the amount of light, which is a normal physiological process that activates when a specific amount of light is required. Dogs have a larger pupil size, which allows more light to pass through and subsequently reach the retina, which is a light-sensitive part of the eye. Thus, dogs have better vision in the dark.

 

Do dogs see in complete darkness? 

Although dogs have developed structures for night vision they are unable to see in complete darkness, a small amount of light is required for the stimulation of light-sensitive cells, which are only stimulated in the presence of light, either dim or full. They have other senses apart from vision, which enable them to detect, respond, or move around better in complete darkness.

 

Dog versus cat vision: 

Even though both cats and dogs are able to see at night, cats have better night vision than dogs, they are able to see in the darkness because they have well-developed tapetum lucidum, which reflects a small amount of light. Pupillary makeup also favors better cat night vision; cats have a vertical slit pupil, which allows a significant amount of light to reach the retina, and consequently, under dim light, better images can be created. 

 

Is it necessary to know about dog eye vision? 

Understanding dog eye vision is crucial to knowing how dogs see and how better they are at seeing distant objects. Knowing about the dog's eye vision and mechanism of vision is necessary for dog owners, whether they rear the dog as a pet or for other purposes. It is crucial during training and hunting episodes. If you have hunter dogs, there is a difference in the vision within breeds, which should be kept in mind while selecting breeds for different purposes. 

 

Dog eyes glow when light falls in the dark. 

Almost every dog owner has witnessed a glow coming from dog eyes just like other mammals' eyes when headlights, flashlights, or other lights fall in the eye. This is due to a membrane found behind the retina, which reflects light. As a result, we notice a glow coming from the dog's eyes.

The color of tapetum when it reflects light ranges from green, blue, and orange, to yellow. During the first three months of life, coloration changes. Blue-eyed dogs don't have a tapetum, so when light falls on their eyes, instead of getting light reflection, their eyes become red. This is due to blood vessels containing blood in the retina.

 

Conclusion: 

Dogs like other mammals are able to see under dim light or at night, for which some light is necessary; in complete darkness, they cannot be able to see anything. Dog eye vision has been discussed comprehensively with comparison of other animals' vision; for canine enthusiasts, understanding dog vision along with other health and body conditions is of utmost importance.