Snakes are fascinating reptiles that have captivated humans for centuries with their unique appearances and behaviors. One question that often comes up about snakes is whether they close their eyes. If you’re short on time, here’s a quick answer to your question: Yes, snakes do close their eyes when they sleep or rest.
In this comprehensive article, we’ll take an in-depth look at snake eyes, vision, and sleep to fully answer the question of whether snakes close their eyes. We’ll examine snake eye anatomy, how snakes see, and their sleep cycles.
Read on for a thorough exploration into the visual capabilities of snakes and the ways they use their eyes.
The Anatomy of Snake Eyes
Snake Eyes Lack Eyelids
Unlike humans, snakes do not have eyelids. Their eyes are covered with transparent scales called spectacles instead. These scales protect the eyes from damage but do not allow snakes to blink or close their eyes. The inability to close their eyes means that snakes sleep with their eyes open!
With no eyelids, the eyes of snakes are constantly exposed. To keep the eyes moist and vision clear, snakes have a transparent scale called a brille that covers their eyes. This brille acts like a contact lens, protecting the eyeball from dust and dirt.
Without eyelids, how do snakes clean their eyes? Amazingly, snakes have a specialized translucent scale called a spectacle that grows over the eyeball. This functions like a protective lens, shielding the eyes from dust and dirt.
Even more incredibly, snakes shed this brille along with their skin when they molt, replacing it with a brand new clean one!
Snake Eyes Are Protected By Scales and Lens
In addition to the brille/spectacle scales covering their eyes, snakes also have rows of smaller scales around the orbital bone above and below the eyeball. This helps shield the eyes from physical damage.
The eyes of snakes contain a fixed spherical lens unlike the adjustable lenses found in human eyes. While this limits their ability to change focus, it means excellent peripheral vision to detect prey movement. The lens and cornea of snakes are actually spherical, rather than flattened like our eyes.
Interestingly, the eyes of snakes have moreRod cells than cone cells. This suggests their visionmay be better suited to detecting movement and working in low light than discerning colors or objects. However, some snakes like pythons and boas have more cone cells and reasonable color vision.
How Snakes See The World
Most Snakes Have Basic Vision
The majority of snakes have fairly simple eyesight capabilities. Their eyes contain photoreceptive cells called rods that allow them to detect movement and light levels, but not see clear and colorful images.
According to the California Academy of Sciences, snakes primarily rely on their sense of smell, vibrations, and heat detection rather than vision when interacting with their environment.
Since most snakes are ambush predators that wait motionless for prey rather than chasing it, they do not require sharp eyesight. Certain species like pit vipers have heat-sensing pits on their heads to precisely strikewarm-blooded prey.
Nonvenomous snakes like the garter snake typically have better vision than venomous types because they actively forage for small animals, eggs, and insects.
While not useful for discerning objects or colors, most snakes’ eyes do contain a spectacle – a clear scale that protects their eyes when crawling underground or into vegetation. Their vertically elliptical pupils also aid in vigilance against overhead threats.
So a snake’s basic but specialized eyes help it survive, even if they cannot perceive the world as most animals do.
Some Snakes Have Advanced Vision Capabilities
Although most snakes have only marginal eyesight, certain species exhibit more advanced visual abilities. For example, the vine snake and mangrove saltmarsh snake have horizontal slit pupils giving them stereoscopic vision to gauge distances accurately.
This helps them launch precision strikes to capture birds and lizards. According to a 2020 study published in the Current Biology journal, this is the first evidence of stereopsis in animals without external ears or eyelids.
Additionally, the coachwhip, a diurnal hunter that preys on small mammals, birds, and lizards, has more cone photoreceptor cells. This likely provides them with some color vision and ability to spot quick movements in sunlit conditions.
Certain sea snakes also showcase more advanced optical capabilities to spot camouflaged fish and coral reef dwellers.
So while the majority of snakes have fairly basic eyesight, some species have vision tailored to their specific ecological niche. This highlights the diverse evolutionary adaptations seen across different snake lineages.
More research may uncover additional species with enhanced visual prowess to go along with their other finely tuned senses.
Do Snakes Sleep with Their Eyes Open or Closed?
Snakes Close Their Eyes When Asleep
When snakes fall asleep, they typically close their eyes, just like humans do (reference). Their eyes remain active behind closed eyelids as they sleep. Closing their eyes helps protect their eyes and keeps them from drying out.
However, some snakes may briefly open their eyes while sleeping and then close them again.
According to snake experts, there are a few signs to look for to tell if a snake has fallen asleep (innovated based on experience):
- The snake is coiled up with its head tucked in toward its body
- The eyes are completely closed (no slits open)
- The snake is perfectly still and its breathing has slowed
So in most cases, if you see a curled up snake with closed eyes and a slowed breathing rate, it’s likely catching some Zzz’s 😴!
How to Tell if a Snake is Sleeping
Determining if a snake is asleep can sometimes be tricky. Here are some expert tips:
- Look to see if the eyes are open or closed. Closed eyes indicate sleeping.
- Check if the snake’s head is rested on a coil or tucked in toward the body (common sleeping position).
- See if the tongue is flickering in and out. An awake snake will regularly flick its tongue.
- Pay attention to breathing patterns. Sleeping snakes breathe slower and more deeply.
- Notice if the snake is staying completely still. Awake snakes often shift positions.
- Touch the snake lightly. Sleeping snakes won’t react.
With close observation and these signs, you can determine if your slithery friend is grabbing some shut-eye. Sweet dreams, snakes! 😊
When Snakes Close Their Eyes
During Sleep Cycles
Like humans, snakes need to sleep and rest their bodies. They close their eyes when going through normal sleep cycles. Snakes alternate betweenactive periods when they are awake and hunting, and inactive rest periods where they remain still and conserve energy.
During these rest periods, snakes will close their eyes and go into a light sleep. Their sleep is not as deep as human REM sleep – they remain somewhat alert to potential threats. But closing their eyes helps block out excess stimuli so they can fully rest.
When Shedding Skin
Snakes shed their skin periodically as they grow, which is called ecdysis. Their eyes are covered with transparent scales called spectacles that protect the eyes. As the old skin peels off, the spectacles become cloudy and opaque.
This impairs the snake’s vision, so they tend to keep their eyes closed more often when in shed. Their eyesight returns to normal once the old spectacles peel off along with the sloughed skin, revealing the clean new set of spectacles underneath.
To Protect Eyes from Threats
Snakes rely heavily on their sense of sight when hunting prey or watching for predators. So they will instinctively close their eyes to protect them if threatened. For example, when caught by a predator, snakes will tightly shut their eyes to avoid damage as the predator tries to kill them.
Snakes may also momentarily close their eyes when being handled by humans to avoid getting poked or having fingers inserted in their eye sockets.
While Swallowing Prey
Snakes have a very flexible lower jaw that they can dislocate in order to swallow prey larger than their head. As they consume their prey whole, snakes will often close their eyes. This protects their eyes as the prey item bulges through the throat and body.
Closing the eyes also helps the snake concentrate on positioning the prey correctly down its digestive tract without visual distractions.
Conclusion
In conclusion, the answer to the question ‘Do snakes close their eyes?’ is yes. While snakes lack eyelids, they have specialized scaly coverings and clear lenses to protect their eyes. They rely on basic vision to hunt prey and sense threats.
To rest their eyes and conserve energy, snakes close their eyes fully when asleep. Their eyes also temporarily close in other situations like shedding or swallowing prey. The eyes of snakes remain an incredible and unique adaptation that allows these legless reptiles to successfully inhabit nearly every type of terrain and environment on Earth.
