While the common emotion people have around snakes is fear, there’s much more to be fascinated about them than there is to fear. Do snakes sleep with their eyes open? Yes. And at the same time no. There will be explanations.
Snakes are a reptile species that come under the subsection of Serpentes that is a carnivorous, elongated reptile without any limbs. Reptiles are generally feared as they are not particularly cozy looking. Most of them rely on the meat of other animals for food, giving them their predatory reputation. Covered in scales, they are cold-blooded animals that rely heavily on external environments to keep themselves regulated.
A rather interesting question around snakes is whether or not their hugely strange list of body anatomy includes not having eyelids. Many people have observed and thus comment on how there have not been many instances where you see snakes blinking or rather sleeping.
This could sound very conspiratorial but many people went around the theory that snakes never sleep. This might confirm them not having any eyelids either, as the main reason for the question. However, that is only a half-truth, as snakes do sleep, even if their eyes are not completely covered behind their lids as humans.
For starters, it will help to clear out that snakes are not some kind of super animals that don’t need any rest or sleep. They do sleep. They just look cooler while doing it. The mechanics of snake eyes and how they work are just very different. Instead of regular eyelids that cover your entire eyes when one sleeps or blinks, snakes have what is called a brille covering their eyes.
Brille is essentially a transparent layer of skin/scale that comes over a snake’s eyes preventing their eyes from being without any shelter. It protects their eyes from unwanted dirt or dust particles just as human lids and lashes do. An even further interesting fact is that when snakes shed their skin, the Brille goes with it too. And only then it is slightly visible, as a milky/cloudy layer when coming off. So usually you will not be able to distinguish the Briller in the eye but when the skin molts, it becomes clearer to spot.
Now that we know for sure that snakes do have something covering their eyes, even if it’s not clearly visible and they do sleep too, you can deduce how it would confuse people. If you ever encounter a friendly snake and it looks like it is about to attack you, likely, the poor animal is just having a power nap.
Few folks already find the whole ordeal of shedding skin strange and eerie. Adding to that the extremely weird fact that their transparent eyelids also shed and get renewed just as the rest of their skin does. It might be a sight of fascination for some, for others, not so much. The actual period that snakes sleep for cannot be determined, as different species have their different habits and require different time for rest.
If you want to find out about some specific snake, various credible zoology reports could help you get to your answers. Instead what would be more helpful is if you find out when snakes are most active, so that you can determine when is the best time to avoid them.
Snakes have what is called circadian rhythm, which is when they are most active and ready for adventures, aka killing and swallowing things whole. Apart from that, certain species just act differently, some are nocturnal and others diurnal. This means they are either more active at night or day, respectively. And some work on a hybrid schedule, being unpredictable as they go about their routine. Some also use the present season as their motivation to rest and prey accordingly.
These were all the answers we had regarding whether or not snakes sleep with their eyes open. To summarise the answer, they do sleep with their eyes open but protected from brille. The layer covering their eyes is just transparent making it look like they are staring when they are resting and sleeping.