1. Starfish
Starfish, also known as sea stars, are marine invertebrates that belong to the class Asteroidea. One of the most distinctive features of starfish is that they do not have eyelids. Instead, they have simple eyespots on the ends of their rays (arms) that can detect light and dark. These eyespots do not provide the starfish with detailed vision, but they do allow the starfish to orient itself and navigate its environment.
2. Jellyfish
Jellyfish are another group of marine animals that do not have eyelids. Like starfish, jellyfish have simple eyespots that can detect light and dark. However, these eyespots are not very advanced and do not provide jellyfish with detailed vision. Instead, jellyfish rely on other senses, such as touch and smell, to navigate and interact with their environment.
3. Snake
Snakes are reptiles that are known for their long, slender bodies and lack of limbs. They do not have eyelids, but they do have clear scales (called spectacles) that cover and protect their eyes. These spectacles are shed along with the snake’s skin during its regular molting process. Snakes are also able to widen and narrow their pupils to adjust to different light levels.
4. Crocodile
Crocodiles are large, semiaquatic reptiles that are native to tropical regions around the world. Like snakes, crocodiles do not have eyelids. Instead, they have a transparent, protective membrane (called the nictitating membrane) that covers and protects their eyes. The nictitating membrane is able to move across the eye to keep it moist and clean, and it can also be used to protect the eye from debris and injuries.
5. Alligator
Alligators are large, semiaquatic reptiles that are native to the United States and China. Like crocodiles, alligators do not have eyelids. Instead, they have a nictitating membrane that covers and protects their eyes. The nictitating membrane is able to move across the eye to keep it moist and clean, and it can also be used to protect the eye from debris and injuries.
6. Gecko
Geckos are small, nocturnal lizards that are native to tropical and subtropical regions around the world. Most gecko species do not have eyelids, but they do have a transparent, protective membrane (called the spectacle) that covers and protects their eyes. The spectacle is able to move across the eye to keep it moist and clean, and it can also be used to protect the eye from debris and injuries.
7. Chameleon
Chameleons are a group of lizards that are known for their ability to change the color of their skin. Most chameleon species do not have eyelids, but they do have a transparent, protective membrane (called the spectacle) that covers and protects their eyes. The spectacle is able to move across the eye to keep it moist and clean, and it can also be used to protect the eye from debris and injuries.
8. Frog
Frogs are amphibians that are found in a variety of habitats around the world. Most frog species do not have eyelids, but they do have a transparent, protective membrane (called the spectacle) that covers and protects their eyes. The spectacle is able to move across the eye to keep it moist and clean, and it can also be used to protect the eye from debris and injuries.
9. Tuatara
Tuataras are reptiles that are native to New Zealand. They are the only surviving members of the order Sphenodontia and are considered to be living fossils. Tuataras do not have eyelids, but they do have a transparent, protective membrane (called the spectacle) that covers and protects their eyes. The spectacle is able to move across the eye to keep it moist and clean, and it can also be used to protect the eye from debris and injuries.
10. Horseshoe crab
Horseshoe crabs are marine invertebrates that are related to spiders and scorpions. They are named for their horseshoe-shaped carapace (shell) and are found in coastal waters around the world. Horseshoe crabs do not have eyelids, but they do have two simple eyes on the top of their head that can detect light and dark. These eyes do not provide the horseshoe crab with detailed vision, but they do allow the animal to orient itself and navigate its environment.
11. Sea urchin
Sea urchins are marine invertebrates that are characterized by their spiny shells and spherical shape. They are found in both shallow and deep waters around the world. Sea urchins do not have eyelids, but they do have simple eyes that are located on the tips of their spines. These eyes are able to detect light and dark, but they do not provide the sea urchin with detailed vision.
12. Lobster
Lobsters are marine crustaceans that are characterized by their large size and distinctive claws. They are found in the coastal waters of the Atlantic and Pacific oceans. Lobsters do not have eyelids, but they do have two simple eyes on the top of their head that are able to detect light and dark. These eyes do not provide the lobster with detailed vision, but they do allow the animal to orient itself and navigate its environment.
13. Shrimp
Shrimp are small, marine crustaceans that are closely related to lobsters and crabs. They are found in a variety of habitats around the world, including oceans, estuaries, and freshwater rivers and streams. Shrimp do not have eyelids, but they do have simple eyes on the top of their head that are able to detect light and dark. These eyes do not provide the shrimp with detailed vision, but they do allow the animal to orient itself and navigate its environment.
14. Crab
Crabs are marine crustaceans that are characterized by their hard exoskeleton and distinctive claws. They are found in a variety of habitats around the world, including oceans, estuaries, and freshwater rivers and streams. Crabs do not have eyelids, but they do have simple eyes on the top of their head that are able to detect light and dark. These eyes do not provide the crab with detailed vision, but they do allow the animal to orient itself and navigate its environment.
15. Mollusk
Mollusks are a group of invertebrate animals that includes snails, slugs, mussels, and squids. Most mollusk species do not have eyelids, but they do have simple eyes that are able to detect light and dark. These eyes are located on the tips of tentacles or on the animal’s head and do not provide the mollusk with detailed vision. Instead, mollusks rely on other senses, such as touch and smell, to navigate and interact with their environment.