This animal’s giant staring eyes are one of its most well-known characteristics. It’s the lemur! This particular lemur has black skin around its eyes – a trait found among the ring-tailed (or Lemur catta) species. As well as being big, a lemur’s eyes are incredibly shiny, due to a reflective layer of tissue called the tapetum lucidum. The function of this layer is to help the little primates see at night – which, since they’re nocturnal, is pretty useful.
Here’s an eye you don’t want to get into a staring contest with! It belongs to a tiger python, which, like all snakes, is utterly unable to blink. This is because snake eyelids are transparent and permanently closed, forming what is known as an ‘eye cap’. This layer keeps the snake’s eye safe while it goes about its day, slithering through the undergrowth, swimming or chasing its prey. And if the cap does happen to get damaged, the snake needn’t worry too much: soon enough they’ll shed it, along with their skin, and get a new one.
Here’s an eye that looks pretty alien compared to our own. It belongs to the blue crayfish, which, as an arthropod, has compound eyes – as you can see if you look closely. Compound eyes are made up of a cluster of tiny tubes called ommatidia. Located at the top of little stalks, a crayfish’s eyes are able to swivel around and keep a good watch out for predators. And, of course, prey…
Here’s a red eye that doesn’t need eye drops. Discus fish, a popular addition to tropical fish tanks, can have either red or yellow eyes. Unless, that is, they’re the offspring of red- and yellow-eyed parents – in which case their own eyes might be (you guessed it) orange. Yet, whatever their eye color, these underwater creatures have evolved to be able to see through cloudy waters, and they dislike bright lights. Still, judging by the nearly neon hue of this pair of peepers, it seems they’re already bright enough themselves!
Here’s a stunning example of sectoral heterochromia iridum (or a dual toned iris) in a husky dog. The reflective quality of the bronze and azure colors make this striking eye look like it could almost be a piece of lacquered jewelry. Siberian huskies are one breed of dog that can have this coloration, which is also called being ‘parti-eyed’. Like many things of beauty, it’s pretty rare in nature.
There’s no mistaking the cold-blooded gaze of a crocodile. We’ve all heard the expression “crocodile tears” in reference to fake displays of remorse, but there’s actually a factual basis behind the saying. Crocodiles do indeed cry while they’re eating – but not because they’re sorry for their prey. It’s thought that air forced through their sinuses by the act of chewing may get into their tear glands, forcing the fluid out via their eyes.
If being surrounded by scales is a giveaway for reptile eyes, then the feathers around this chocolate-brown orb can only mean it belongs to a bird. A lark, in this case. Birds’ eyes are actually similar in many ways to the reptile eyes from which they evolved. For one thing, birds have eyes that are flatter in shape than the spherical eyes of mammals like humans. What this means in practical terms is that our feathered friends can focus on a much wider field than we can. It’s not called eagle-eye vision for nothing!
Here’s an unusual looking eye – although it belongs to a relatively common bird: the macaw parrot. Just as humans use their eyes to convey various emotions, parrots are known to perform a display called ‘eye pinning’ or ‘eye flashing’. This involves them expanding and contracting their pupils in a way that can look quite disconcerting to those who are unfamiliar with it! Rather than think that Polly is having some kind of fit, however, onlookers can rest assured that ‘eye pinning’ is simply a kind of avian communication, with the parrot using this technique to signal that it is happy, agitated, or maybe even just curious.
If this eye looks familiar, that’s because it belongs to one of our closest relatives, the chimpanzee. But the similarities don’t end with appearances. Like humans (but unlike other animals) the great apes are able to distinguish between a wide range of colors. This ability is called trichromacy, and is one of the reasons we can appreciate sights like oil paintings, stunning sunsets… and the images in this article!
We’re not sure exactly what species of fish this eye belongs to, but we love its beautiful amber coloring. Although this one may look dissimilar, the eyes of fish really aren’t that different from our own. Like ours, they have retinas, pupils, irises, lenses, and corneas – like the exquisitely colored dome seen here. One of the ways our water dwelling friends’ eyes do differ from ours is their lenses. While ours sit flat, fish lenses are spherical and protrude through the pupil opening, giving them that slightly comical, goggle-eyed look.
This is the lovely brown eye of a bunny rabbit. Rabbits have famously large eyes and, as you can see here, quite long eyelashes, too. Bunny mascara, anyone? Like all the other animals on this list, rabbits’ eyes have evolved to suit their particular needs. For these cute little creatures, that means being able to detect movement even if it’s a long way off. That way they have plenty of time to dive into their burrows to avoid a hawk or a fox (to say nothing of Elmer Fudd), either of which might be thinking about a tasty bit of rabbit for lunch…
This furry critter likes to keep its eyes open even when it’s asleep! And when you’re a cute, cuddly but relatively defenseless guinea pig, that’s probably a good idea. As adorable as they are, guinea pigs also have some habits that might seem a little icky – like extruding a milky white substance from their eyes, which they then use to groom themselves. Something you might not want to think about the next time you’re petting one…
These long eyelashes are a feature we would definitely expect to see on a horse, but the deep blue lens is a delightful surprise. A horse’s lovely big eyes aren’t just there to look attractive, though. Animals like horses and cows have large eyes so that they can see even in poor and low light. Very useful if you suddenly find yourself face to face with a hungry nighttime predator!
This lovely brown, almond-shaped eye belongs to a cunning hunter and scavenger, the hyena. Remarkably, spotted hyenas are the only meat-eating mammals born with their eyes open. In folklore, it was believed that hyenas’ eyes contained a stone which, when placed under the tongue, enabled a person to predict the future. We’re not sure we’d like to try approaching a hungry hyena to find out if this ‘stone’ really exists!
The scaly-looking skin around this eye quickly tells us that it belongs to a reptile – an iguana, in fact. Iguanas have very keen eyesight and can see well even from a distance. This superior vision is important both for finding their way around their naturally cluttered jungle habitat and for looking for prey. But that’s not all! Iguanas also have a transparent scale on their head known as a ‘parietal eye’ which can pick up changes in light – like the shadow of a predatory bird, for example. Nature really is amazing when it comes to adapting for survival…
Here’s another primate eye, this one belonging to a macaque. In a similar way to the eyes of their human cousins, monkeys’ eyes face forward, and macaques – like chimpanzees and some other primates – are able to see the same range of colors that we do. It’s speculated that our ancestors evolved this color recognition so that they would know how to identify different kinds of fruit and insects – an essential ability if you want to pick the kinds that are good for you rather than those that will make you sick.
This image of an eye is a little different from most of the others collected here in that it’s a side view. And what an amazing view it is! The transparent cornea of this British shorthair cat reminds us a little of a space helmet, complete with tiny reflections of stars.
This is the eye of a Siamese cat, and from this gorgeous image, it’s no wonder this breed is known for its striking blue eyes. Unfortunately, this beauty comes at a price: Siamese cats lack the ability to see in low light that their darker-eyed cousins have. They are also more at risk of having crossed eyes than other felines, although breeding has diminished this trait in the Siamese cats of today.
Here’s an eye that looks more like a transparent button! It is actually the eye of a zebrafish, the study of which may actually help visually impaired humans. It has been known for a while that zebrafish eyes are able to regenerate even after considerable damage. Now it is believed that the cells responsible may also be used to heal retinal damage in people – further proof of just how beneficial the study of animal eyes can be!
Whether they’re large or small, bulging or flat, plain or multi-colored, animal eyes really are remarkable. So the next time you’re with your pet or on a farm, or anywhere else you might find yourself in the company of critters, take a look into their eyes. You might be surprised by what you find looking back at you!