Snakes are fascinating creatures that capture people’s imagination. One question that often comes up is: do snakes blink? Blink is the rapid closing and opening of the eyelid. If you’re short on time, here’s a quick answer to your question: Yes, snakes do blink, but not in the same way humans do. In this article, we’ll take an in-depth look at snake eyes, blinking, and vision.
We’ll cover how a snake’s eyes work, how their eyelids function, reasons for blinking, and differences between snakes and humans when it comes to blinking and vision. We’ll also bust some common myths about snakes and blinking. Read on to learn all about this intriguing topic!
Anatomy of Snake Eyes
Eyelids
Unlike humans, most snakes do not have movable eyelids. Instead, they have a transparent scale called a spectacle that protects their eyes. This clear scale is shed along with the rest of the snake’s skin when it molts.
Some snakes, like pythons and boas, have movable “brille” scales that cover their eyes while they are resting. This helps protect their eyes since they don’t have eyelids.
Without movable eyelids, it was long thought that snakes could not blink. But high-speed video has revealed that snakes actually do blink – just in a different way than humans. Instead of lowering an upper eyelid over a stationary eye, snakes blink by retracting their eyeball deeper into their head and closing the spectacle scale over it.
This happens in an instant, often just a few times an hour. Blinking helps spread tears over the surface of the snake’s eyeball to keep it moist.
Lenses and Pupils
Snakes have excellent eyesight for detecting and tracking prey movement. Their eyes contain a spherical lens that focuses light. Unlike the flat, round pupils of humans, snakes have vertically-slit pupils that can open wide to let in more light or close tightly to protect their sensitive eyes.
This helps them see well in both bright and dim conditions. Many snakes, like pit vipers, boas and pythons, also have heat-sensing pit organs on their faces that aid in targeting warm-blooded prey.
Some key facts about snake lenses and pupils:
- Snakes can see well up close and at a distance.
- Slit pupils allow precision focusing on near and far objects.
- Wide pupil openings optimize vision in dim light.
- Narrow pupils protect eyes from bright sunlight.
- Pit vipers have heat-sensing pits to detect infrared radiation from prey.
Retina
A snake’s visual acuity ranges from average to excellent, depending on the species. Most non-venomous snakes have fairly good eyesight. Venomous snakes like cobras and vipers tend to have excellent vision to target prey accurately when striking.
Here are some key facts about the snake retina:
- Contains two types of photoreceptor cells: rods for night vision, cones for day vision.
- Some snakes have mostly rods, like boas that are active at night.
- Diurnal snakes like racers have more cones than rods for better daytime vision.
- Tree snakes have forward-facing eyes with excellent binocular vision.
- Pit vipers can visually detect prey up to 30-40 feet away.
So while snakes may not blink in the usual way, they have remarkable eyes adapted for hunting and survival. Their specialized pupils, lenses, retinas and even spectacle scales allow these incredible reptiles to see the world around them with stunning visual clarity!
Do Snakes Blink?
Yes, snakes do blink, but not as frequently as humans. They have transparent eyelids called brille that protect their eyes. Blinking helps to keep their eyes moist and clear of debris.
Yes, But Not Frequently
Snakes don’t have typical eyelids like mammals. Instead, they have a clear scale called a spectacle or brille that covers and protects their eyes. This brille allows them to see while also maintaining moisture on the eye’s surface when closed.
However, snakes only blink around once per minute, compared to the average person’s blink rate of 17 times per minute.
Transparent Eyelids
The brille serves as a permanent transparent eyelid for the snake. Below that, the snake has a lower eyelid that closes upwards to distribute tears across the eye. Since the brille shields the eyes from things like sand and dirt, snakes don’t need to blink as often as animals with exposed eyeballs.
Blinking to Moisten Eyes
When snakes do blink, it helps lubricate their eyes with tears and remove debris. Their eyes don’t have much exposed tissue, so they produce fewer tears. Slow blinking spreads tears evenly across the eyeball surface underneath the brille.
So while infrequent, blinking remains an important mechanism for maintaining clean, functional snake eyes.
Blinking When Shedding Skin
Increased blinking may occur when snakes are preparing to shed their skin. According to ReptileKnowHow.com, the old brille detaches with the rest of the skin. Blinking helps loosen the older brille scales before molting and makes way for brand new spectacle scales underneath.
Once the skin has shed, blinking returns to a more normal, infrequent state.
Differences Between Human and Snake Blinking
Humans Blink Frequently
Humans blink quite often, usually around 15-20 times per minute on average. Blinking helps spread tears across the surface of the eye to keep it moist and clear of debris. Frequent blinking also momentarily shuts off visual input, which may help the brain process visual information.
While we don’t consciously control our blinking, factors like fatigue, eye irritation, and concentration can affect blinking rate.
Snakes Blink Slowly
Snakes, on the other hand, blink very infrequently – just once or twice an hour typically. Their eyes are covered by transparent scales called spectacles that protect them from dirt and keep eyes moist between blinks.
As snakes are ambush predators that rely on patience and stillness to catch prey, slow blinking helps them maintain focus without distraction.
Purpose of Blinking Varies
For humans, frequent blinking maintains eye health and visual processing. Snakes, however, blink primarily to clean their eyes and spread moisture. Their unique spectacles allow them to blink minimally without compromising vision.
So while both humans and snakes blink, the purpose and frequency differs greatly between the two.
Other Aspects of Snake Vision
Limited Color Vision
Compared to humans, snakes have relatively poor color vision. They primarily see in shades of gray, green, and purple. Some species, like pit vipers, boas, and pythons, likely only see in shades of gray.
However, other species, like garter snakes and milk snakes, may have more enhanced color vision ranging into the green and ultraviolet spectrum. This allows them to spot the subtle movements of prey like frogs and insects which reflect green and UV light.
Motion Detection
A key strength of snakes’ vision is detecting motion. Their rectangular-shaped pupils and high density of rod photoreceptor cells give snakes excellent sensitivity to movements in low light. This helps them hunt prey at night and also detect approaching predators during the day.
Several adaptations like an uncoiled posture, horizontally elongated pupils, and laterally placed eyes give snakes a wide field of binocular vision. This allows them to accurately judge distances and detect tiny movements in their periphery.
Interestingly, some studies show that a snake’s visual processing centers in the brain are highly developed compared to the optical structures of their eyes. This indicates evolution has prioritized neural pathways that facilitate quick reaction times to spot and capture elusive prey rather than clarity of static vision.
So while not the sharpest eyesight, a snake’s visual system is finely tuned to notice motion.
Heat-Sensing Pits
In addition to their eyes, certain groups of snakes like pit vipers and some boas and pythons have heat-sensing pit organs. These special receptors can detect the infrared radiation emitted by warm-blooded prey.
Essentially, this gives snakes a sixth sense to precisely strike prey even in total darkness. Each pit organ contains a membrane sensitive to temperature differences as slight as 0.003°C. As the snake draws nearer to a target, the membrane detects increasing heat intensity, allowing the snake to accurately aim its strike.
These heat-sensing pits provide pit vipers and similar species a tremendous hunting advantage.
Conclusion
To summarize, snakes do blink their eyes but not as often or in the same manner as humans. Their eyelids are transparent and used primarily for lubricating their eyes and protecting them while shedding. Blinking frequency varies by species.
While snakes may not rely much on vision, their highly adapted eyes allow them to detect motion and infrared radiation emitted by prey. The unique aspects of snake eyes and blinking highlight the diversity of vision capabilities that have evolved in different animals.
