Crocodile eyes have evolved over millions of years to have some amazing characteristics. Did you know that crocodiles have night vision? They can also see when they are swimming underwater! They use their built-in goggles to cover their eyes in the water. If they get in a fight, they can retract their eyeballs into the sockets to protect them. Sounds like a super robot! Let’s take a look at crocodile eyes and what makes them so unique!
What Do Crocodile Eyes Look Like?
Crocodile eyes are about the same size as human eyes (around 24 mm wide or slightly smaller than a gumball!). They can be a variety of colors from brown to green and have a pupil similar to cats. Crocodiles have a vertical slit for a pupil and can close it so that it is a very narrow line. Their eyes are located on the top of their head so that they can wait and ambush prey. They often hide below the water surface with just their eyes and nostrils above the waterline.
Do Crocodiles Really Have Night Vision?
Yes, crocodiles have night vision. They can see at night because of tiny mirrored receptors in the back of their eyes. Their pupils can also completely open at night to help them see better. Though, they wouldn’t be able to read their favorite magazine because their night vision is not that clear. But they can make out the outline of fish, crustaceans, deer, zebra, or whatever might be their next meal. Because crocodiles are apex predators, they do not have any threatening predators to watch out for, but they can spot a fellow unwanted crocodile that suddenly appears in their territory.
Can Crocodiles See Underwater?
Yes, crocodiles can see underwater! The same mirrored receptors that help crocodiles see at night help them see underwater where it is much darker. Much of the water crocodiles live in are brackish backwaters and can be quite muddy. These receptors help them make out the outline of fish and other prey enough to hunt underwater and successfully find food.
Do Crocodiles Have Built-In Goggles?
Crocodiles have an eyelid that covers the eyes underwater. The third eyelid is transparent so the crocodile can make out shapes enough to see fish and crustaceans underwater but also to be able to see if a larger mammal comes to the edge of the water for a drink. Crocodiles can use their powerful tail to vault out of the water and attack unsuspecting prey. Using their strong jaws and jagged teeth, they pull the animal into the water and drag it under, rolling it over and over until it drowns. They then bite off chunks and swallow the chunks whole.
How Many Eyelids Do Crocodiles Have?
Crocodiles have three eyelids. They have one on the top and bottom that come together to protect and hydrate the eye. They also have a third transparent one that crosses over horizontally, providing protection when they go underwater.
Can Crocodiles See Color?
Yes! It is believed that the receptors in their eyes are able to recognize colors, both on land and underwater.
How Do Crocodiles Protect Their Eyes In A Fight?
Crocodiles can retract their eyeballs into the sockets to protect them in a fight. They also have a heavy fold of armored skin above each eye. There are a few other animals that can retract their eyes, like some frogs and whale sharks, but researchers found the giant guitarfish can retract its eye almost 1.6 inches back in its head! Guitarfish look like small sharks with a stingray for a head. They spend a lot of time at the bottom of the ocean, foraging through the sand, and can retract their eyes to protect them from a feisty crab they are trying to catch for dinner.
Do Crocodile Eyes Glow At Night?
Yes! When light shines on their eyes at night, their eyes appear to glow red. Conservationists use “spotlight surveying” to count crocodile populations for research. For example, the saltwater crocodile is considered critically endangered in Myanmar. The only known populations are at the Meinmahlakyun Wildlife Sanctuary. They can count the crocodiles at night by counting their glowing eyes and get a better idea of how many there are and what environments they prefer. In this study, they found the optimal conditions were low salt streams that were not around humans.
Do Crocodiles Have Good Peripheral Vision?
Yes! First, crocodiles have eyes that are uniquely placed on their head. If you look at them from the front, it looks like they are looking at you. If you look at them from the side, it looks like their eyes are on the side. This gives them the advantage of having very good peripheral vision. Secondly, they have a horizontal line of special receptors (called a fovea streak) that extends across the eye. As you read this, you have to shift your eyes slightly to follow the words. The fovea streak allows crocodiles to scan the horizon without moving their eyeballs. So, if you want to retrieve your golf ball from the water hazard on hole 8 and it looks like the crocodile is looking the other way, it can probably still see you!
Do All Crocodile Species Have The Same Eyes?
A recent research study shows that saltwater and freshwater crocodiles have different cone cells (that help them detect colors) in their eyes. There is more long-wavelength light in freshwater and less long-wavelength light in saltwater. For example, the color red has the longest wavelength at 700 nanometers, and violet has the shortest wavelength at 380 nanometers. This research study concludes that crocodiles have eyes that adjust to being the best fit for their environment.
Can Crocodiles See Better Than Humans?
Crocodiles cannot see as well as humans, but they have very good eyesight. On the one hand, they can’t see as precisely as humans, but on the other hand, they can see at night. If you see a crocodile, be sure to assume it can see you and not wait to make eye contact. American crocodiles are not as aggressive as Nile or saltwater crocodiles, but you should not take any chances.
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