World’s Deadliest Predators: Best Eyesight
Humans are complex, intelligent beings and yet, when compared to some animals, we lack the skills, speed, and awareness of these unique creatures, making us appear weak and uncoordinated. In terms of eyesight, we can see a fair distance but only in light and only ahead of us. This is a shortlist of the world’s most magnificent animals equipped with super eyesight, able to easily detect movement, heat, and even electrical impulses.
Hawk-eye and eagle-eye vision have become common terms to describe eyesight with incredible clarity and long-distance abilities. Eagles, hawks and buzzards are natural predators which prey on small mammals such as rabbit and mice. When flying high above the ground, they naturally need to be able to notice their prey below. These birds have vision which is 3x sharper than our own and able to spot prey from miles away. It is believed that their view of the world is magnified and enlarged because, whilst an eagle’s eye weighs around the same as that of a human, the back of the eye is wider and flatter, meaning the projected image will be larger. In addition, the retina of an eagle eye has a higher concentration of the cells which send information to the brain. Whilst we have around 200,000 cells per millimetre, an eagle has over 1 million. In eagle territory, the mice and rabbits don’t stand a chance.
Renowned as kings of the underwater world, sharks are natural predators. Like eagles, their survival depends almost entirely on their ability to hunt prey, often portrayed as a blood lust due to film favourite Jaws. Like a human, a shark’s eye contains a cornea, retina, pupil and lens, but the difference lies in their ability to detect electrical currents or vibrations, and chemical changes in the water. So perhaps Jaws wasn’t so implausible; the vibrations of a swimmer’s legs would send enticing signals to the nearest shark. At the back of a shark’s eye there is also layer of mirrored crystals (tapetum lucidum) which allows light to pass through the retina for a second time. As a result, sharks are able to see clearly in dark of murky water up to 10 times better than a human can see in clear water.
So far, we’ve covered distance vision and underwater vision; next up, it’s thermo-vision. Snakes have the unique ability to detect body heat using temperature-sensitive organs between their eyes and nostrils. This means they can ‘see’ radiated heat from warm-blooded mammals. This makes them the ideal predators as they are able to see in any conditions and silently sneak up on their prey.
Both domestic and wild cats have long been praised for their keen night-time vision. Like sharks, the back of a cat’s eye contains tapetum lucidum cells which reflect light back through the retina, explaining their reflective quality and their technology replicated for road safety lights. The pupil of a cat’s eye can also dilate to allow more light to enter, hence their improved night-time vision. Similarly, during the day, their pupils can constrict to prevent them from being dazzled by sunlight. This explains why sometimes a cat’s eye looks almost entirely black. In addition, cats have an extra ‘third eye’ which is a protective membrane beneath the eyelid. When dozing, this membrane can sheath the eyeball, ready to quickly return to its original position if the cat is woken by movement or sound.
They may largely be seen as household pests but some insects have unique visual abilities. Insects’ eyes are made up of hundreds of faceted single eyes called ommatidia, each providing one part of an overall picture. These are called ‘compound eyes’ and may be understood like a digital pixel forming part of the image. With these features, the eyes of an insect are able to detect movement easily, perhaps explaining how they always manage to avoid that fly swat…
So whilst we may not be able to spot a mouse from 10 miles away or see underwater, eyesight has naturally evolved to suit the needs of every creature. And though our capabilities may seem poor in comparison, we’ve still got one thing which keeps us ahead of the others… opposable thumbs.
Victoria is a writer for glasses frames supplier, Direct Sight