Posted by: courtneygrapperhaus | July 12, 2015

Animal Vision – Who Has The Best?

St. Louis is fortunate to have a wonderful zoo with free admission. I love their slogan “Who’s watching who at the St. Louis Zoo?” Did you ever wonder which animals have the best vision? Scientists estimate that there are as many as 10 million species of animals on Earth. These are some of my favorites that have exceptional vision.

Dragonflies

Dragonfly

Dragonflies can see many more colors and details than humans due to their increased number of light sensitive proteins called opsins.They can also see UV light and have polarized vision.

Most insects have multifaceted eyes and dragonflies have the most at an estimated 30,000. Each one of these creates its own image. They have an almost spherical view.

Mantis Shrimp

mantis shrimp 2Many scientists refer to the mantis shrimp as having the most advanced eyesight of all creatures.

Humans have 3 color receptive cones. The mantis shrimp has 16.

“Each eye possesses trinocular vision and depth perception” Wikipedia

Like dragonflies, they can see UV wavelengths and have polarized vision.

Birds of Prey

bald-eagle_1_600x450Birds of Prey, such as eagles, hawks and falcons, have especially large eyes which let in a lot of light and give a large view. Birds of prey also have a lot of receptors which maximize visual acuity. They have both a central and lateral fovea (most other animals have only one).

Birds focus on their target by changing the curvature of their eyes. They have great binocular vision because of the placement of their eyes.

Predatory birds such as eagles and hawks have the largest and most elaborate pecten of all the birds. The pecten supplies nutrients and oxygen throughout the vitreous humour of the eye, thereby reducing the number of blood vessels in the retina. With fewer blood vessels to scatter light coming into the eye, raptor vision has evolved to be the sharpest vision known among all organisms. (www.ebiomedia.com)

Chameleons

chameleon“The chameleon’s specialized vision and a specialized tongue-projection system permit the capture of insects and even birds from a distance. The chameleon’s eyes are very good at detecting and regulating light. The lens of a chameleon’s eye is capable of focusing extremely rapidly, and it can enlarge visual images much like a telephoto lens.” (www.britannica.com/animal/chameleon-reptile)

Four Eyed Fish

4 eyed fish“Despite their name, four eyed fish have only two eyes. However, these eyes are divided by a band of tissue and each half of the eye has a pupil of its own. This bizarre adaptation allows the four eyed fish to see perfectly (and at the same time) both above and below the waterline, scanning for both prey and predators.

The upper half of the eyeball is adapted to vision in air, while the lower half is adapted to underwater vision. Although both halves of the eye use the same lens, the thickness and curve of the lens is different in the upper and lower eye halves, thus correcting for the different behavior of light in air and water. This means that when the four eyed fish is completely submerged, the upper halves of the eyes are out of focus. Fortunately, the fish spends almost its entire life in the surface, and it only has to dive completely once in a while to prevent the upper halves of the eyes from dehydrating.” (listverse.com)

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