Everything in this world makes sense because of our eyes. Eyes are one of the most fascinating and complex parts of our body but many of us do not really know how they actually work. Every living being on earth heavily relies on their eyes for their day-to-day tasks.
It is believed that eyes first developed in animals around 550 million years ago! Another fascinating fact about our eyes is that we don’t actually see through them. We see through the brain and our eyes act as a camera, sending signals to the brain to process those pictures.
The iris works like the diaphragm of a camera and controls how much light reaches the back of the eye. It automatically adjusts the size of the pupil and in this way, functions like a camera’s aperture.
9. Spookfish
Width of Eyes: 0.15 inch
The spookfish has eyes with a width of 0.15 inches. This is a bizarre animal that was discovered 120 years ago but nobody ever realized how big its eyes were as it had never been caught.
However, now the researchers say that this strange animal does not have four eyes but instead is the first known vertebrate to use mirrors. The spookfish uses mirrors rather than lenses to focus light in its eyes.
It looks like the spookfish has four eyes because each of its eyes is split into two connected parts. One half of this eye points to the ocean upwards, giving a view of the potential food above while the other half that points down looks like a bump on the side of the head of the fish. Such eyes are called diverticular and are unique among all vertebrates.
8. Kim Goodman
Width of Eyes: 0.47 inch
Kim Goodman can willingly make her eyes pop out of her head at a title-holding distance of 0.47 inches. She is one of the four more recognized record-holders for her unique condition “Proptosis.”
A resident of Istanbul, she discovered her abilities one day after being hit in the head with a hockey mask.
7. Ogre Faced Spider
Width of Eyes: 0.50 inch
The ogre-faced spiders are known for their massive eyes which reach to widths of as much as 0.50 inches. These spiders hide themselves during the day and hunt at night. They not only have a great sense of vision but alsopossess incredible hearing senses which makes it much easier for them to hunt their prey.
They can sense their predators from as far as 2 meters away. Besides this, they can also hear the low-frequency sounds that are emitted by insects.
6. Philippine Tarsiers
Width of Eyes: 0.62 inch
Compared to the size of any mammal, the tarsiers have the largest eyes. Each eyeball measures almost 16 millimeters in diameter and this is approximately the size of the Tarsier’s brain. In fact, their eyes are so huge that they can’t even rotate them!
However, they can rotate their necks 180 degrees in either direction, just like the owls do. The tarsiers make use of this ability by waiting silently for their prey and then suddenly grabbing it.
5. Dragonfly
Width of Eyes: 1 inch
When compared to its size, the body of a dragonfly is comparatively small. For reference, if you were a dragonfly, then your eyes would be the size of a football helmet! Each eye of a dragonfly is made up of 30,000 telescope-shaped ommatidia.
The dragonfly collects light from its huge eyes and then its brain processes this light to provide a 360-degree view. However, since they have compound eyes, they can only look at things that are closer to them clearly.
Depending on their incredible vision, these dragonflies hunt for food and also for mating purposes.
4. Elephant
Width of Eyes: 1.4 inch
Unlike humans, an elephant’s eyes are located on the side of its head. The size of an elephant’s eyes is about 1.4 inches in diameter. However, despite their huge eyes, elephants have poor vision. This is because an elephant is huge in size and compared to that, the eyes are quite small.
Besides, the location of its eyes also poses a hindrance. These large mammals can only see up to short distances of up to 25 feet away. Aside from elephants not having good vision, elephants are colour blind. One of the less known elephant vision facts is that color-blind humans and elephants share the same set of visual pigments. Elephants can see blues and yellows, but cannot distinguish between reds and greens.
3. Ostrich
Width of Eyes: 2 inch
The Ostrich (Struthio camelus) is said to have the largest eyes of any land animal. They are about the size of a billiard ball and five times larger than the human eye! You can see when you look closely that their eyes are quite beautiful with long eyelashes to protect them.
However, they take up so much room in their head that their brain is actually smaller than either one of its eyeballs. With such impressive eyes, ostriches can spot moving objects at great distances – something around the size of a large dog can be seen as far as 3km away during the day and about 50 meters at night.
The ostrich needs its large eyes to protect it from the variety of intimidating predators that it faces in life on the African savanna.
2. Blue Whale
Width of Eyes: 6 inch
Eleven species of whales live in waters around the globe, and eye size varies according to whale type. Species include sperm whales, humpback whales, minke whales, Bryde’s whales, Sei whales, fin whales, blue whales, beluga whales, false killer whales, pilot whales and orca whales, also known as killer whales.
An adult gray whale’s eyes are about the size of baseballs, or about 3 inches across. Her eyes are set about 8 feet away from top of her jawline. A blue whale’s eyes are bigger, at about 6 inches across.
This is about the size of a cow’s eyes — seemingly small, considering she’s the largest animal on earth. Interestingly, all other blue whales have relatively small eyes for their body size – each about the size of a grapefruit – and their eyesight is thought to be weak. They have no tear glands or eyelashes.
1. Colossal Squid
Width of Eyes: 11 inch
The colossal squid has the largest animal eyes ever studied. In a living colossal squid the eyes measure about 27 cm across — about the size of a soccer ball. Another incredible feature of the colossal squid is that the eyes are equipped with light organs.
The colossal squid possibly has the largest eyes that have ever existed during the history of the animal kingdom.
Vision is very important to colossal squid. They use their eyes to see and catch prey, to watch for predators, and to see each other. With huge eyes and built-in headlights, the squid is well equipped for life in the dark depths of the Southern Ocean.
The colossal squid’s eyes are placed so they face forward, giving the squid binocular, or stereoscopic, vision. The giant squid, in contrast, has eyes placed on each side of the head. It can see forwards and behind to detect predators, but does not have the binocular vision needed to judge distances.
