The eyesight of humans differs from that of hedgehogs. Relative to humans, the vision of hedgehogs is not topnotch. But does this mean they cannot see? Let us find out.
Can hedgehogs see? Yes, they can. Hedgehogs might have poor eyesight, but they can see.
However, what they see is not as detailed as what humans see. Also, the extent and depth of their sight is a far cry from what is obtainable in humans.
To further satisfy your curiosity about the topic, we discuss the vision of hedgehogs in the rest of this article. We talk about their eyesight at birth, the organs they rely on for perception, and much more.
Can Hedgehogs See?
Hedgehogs can see but not as well as humans. Their vision is poor but not inexistent.
There have been studies on the composition of the eyes of hedgehogs compared to other mammals. While hedgehogs’ eyes contain rods like every other land mammal, they typically contain little or no cones.
Rods are eye cells in charge of low light vision. They are not involved in the perception of color, and they have relatively low spatial acuity.
Cones, unlike rods, are responsible for vision in bright light. They are involved in the perception of color, and they have high spatial acuity.
What is the significance of rods and cones in hedgehogs? Well, since they typically have rods and little or no cones, hedgehogs have poor depth perception.
Their binocular vision is imperfect, and they also have poor color perception. But the good news is they are nocturnal. So, depth and color perception are not of utmost importance to their survival.
Hedgehogs might not be able to see as we do. However, they see shapes and the outline of objects, such as houses and trees, in low light.
Hedgehogs can also see when objects move in low light. That being said, it is suggested that hedgehogs can have limited color vision if they are trained.
Are Hedgehogs Born Blind?
Yes, hedgehogs are born blind. But within 14 days, their eyes usually become more functional.
Vision is not the only function absent in hoglets. They are also born deaf and without spines. But these functions also develop as the days pass.
How Do Hedgehogs Sense Things?
As we already explained, the vision of hedgehogs is not great. Fortunately for them, it does not matter too much because of their other senses and because they are nocturnal.
So, besides using their eyes, how do hedgehogs sense things? Other senses hedgehogs use to perceive stimuli include olfaction, tactility, and hearing.
The sense of smell (olfaction) in hedgehogs is thought to be one of the most vital ones. As a matter of fact, it might be the most important one.
The importance of smell in hedgehogs is demonstrated by their constant sniffing of the air around them.
Hedgehogs typically sniff the air while they move. This way, they can detect other hedgehogs, food, intruders, and other scents.
Besides their sniffing habits, the morphology of their snouts indicates the importance of the sense of smell to hedgehogs.
Hedgehogs have a moist tip at the end of their long snouts. This tip is called a rhinarium. It is suggested that this tip becomes extra wet when a hedgehog perceives the scent of a stranger.
Typically, moisture aids the sense of smell in mammals as it dissolves airborne substances. So, the snouts of hedgehogs may get wetter as they try to smell.
Besides smelling, hedgehogs may also rely on tactility (touch) for sensing. Many tactile sensors are located in the long guard hairs around their spines. Some of these sensors are also in the areas around their faces.
Apart from smell and touch, hedgehogs also sense stimuli with their ears. Their ears might be small, but hedgehogs have a decent sense of hearing.
A study from Vanderbilt University suggests that hedgehogs can hear within 250 Hz to 45 kHz. Some other studies suggest that some species might be able to perceive sounds up to 85 kHz.
The ability of hedgehogs to perceive sounds of high frequencies aids them as prey and predator. When they hear loud or threatening sounds, they take a defensive stance or hide.
On the other hand, their hearing helps them locate their prey and orient themselves to capture it.
Blindness in Hedgehogs
We mentioned earlier that hedgehogs are born blind, but their eyes become functional within a few weeks. Well, hedgehogs may still become blind later in their lifetime. Fortunately, blindness is not a common occurrence in hedgehogs.
Nonetheless, we will explore some of the causes of blindness in hedgehogs and how you can help a blind hedgehog survive.
Causes of Blindness in Hedgehogs
The following are some of the causes of blindness in hedgehogs:
- Congenital defect
- Trauma or injury to the eye
- Nerve issues
- Ocular Proptosis
- Mite infestation
A hedgehog may be blind because of certain genetic traits or mutations. You can avoid this by getting your hedgehog from an ethical breeder.
The chances of getting a blind hedgehog from an ethical breeder are pretty low. Such breeders follow the lineage of their hedgehogs. Then they prevent the breeding of genetic traits that can cause defects.
If somehow you get a hedgehog that suffers from congenital blindness, do not breed it. Doing so would be unethical.
Hedgehogs can get cataracts just like humans. It might even be one of the most common causes of blindness in hedgehogs. Just like humans, cataract is more common in older hedgehogs.
The adversity of cataract on hedgehogs is not as harsh as most other causes. The loss of sight is gradual, so in a way, the hedgehog becomes accustomed to its situation before complete blindness sets in.
Like humans, hedgehogs may also suffer from glaucoma. Glaucomas are a group of diseases that damage the optic nerves, which ultimately leads to blindness.
The damage caused by glaucoma stems from a build of fluid pressure in the eye. Besides damaging the optic nerves, this buildup may also cause pain in the affected eye.
Trauma or Injury to the Eye
Hanging water bottles typically cause trauma to the eyes of hedgehogs. All it takes is for the water bottle to be suspended incorrectly, and the hedgehog may just crash into it.
With their eyes protruding, such hedgehogs will likely go blind from the crash. But this can be avoided if the water bottle is placed at a height where they cannot stumble on it.
Hanging water bottles are not the only cause of trauma to the eye of hedgehogs. However, they appear to be the most common cause.
Hedgehogs may also go blind from nerve issues not related to glaucoma. In one such case, the hedgehog went blind, then a while after, it lost its sense of smell. Later, it was discovered that the hedgehog consumed some polyester fiber, which damaged some nerves.
A hedgehog may also have ocular proptosis, and this may lead to blindness. Ocular proptosis is a condition in which the eye of a hedgehog sticks out of the socket.
The chances of recovery from ocular proptosis are low. In many cases, the affected eye is removed. Ocular proptosis may be caused by an injury to the eye, a tumor, and many other diseases.
It is a condition that must be treated immediately. So ensure you get the affected hedgehog to a vet clinic right away.
The mite known as the Eurasian Hedgehog Mange Mite (Caparinia tripilis) is another cause of blindness in hedgehogs.
When this mite infests a hedgehog, it causes hair loss, quill loss, and lesions around the eyes. If left untreated, the affected eyes may go blind.
How to Help a Blind Hedgehog Survive
If you have a blind hedgehog, you can help it adapt to its condition by doing the following:
- Reduce the size of its cage so it would not have to maneuver too much to get around.
- Stop using a hanging water bottle for the hedgehog. Instead, place its water right by its food. This way, it is easier to find.
- Always ensure that you set everything down in the same position every time: water, food, and other things they need.
- Observe the hedgehog and make adjustments based on your observation. If you cannot spend enough time observing it yourself, get a cage camera. Let the camera record the hedgehog while you review the footage for possible improvements later.
Hedgehogs might not have the best vision, but under normal circumstances, they are not blind. Lucky for them, they are nocturnal animals, so sight is not very vital to their survival. Then again, their sense of smell, touch, and hearing makes up for their lack of vision.