Do Humans Have The Best Eyes?

Human Eye, Photo: http://buytaert.net/eye

Human Eye, Photo: http://buytaert.net/eye

The short answer is “no”. We cannot see in the dark, we cannot really focus on things far and our field of view is only about 180 degrees which means we do not see half the stuffs around us. There are lots of animals who have better vision than human.

First consider the color vision. For visualization, there are millions specialized type of neuron in the retina called Photoreceptor cells. These Photoreceptor cells can be classified mainly into two groups; rods and cones. Rods are extremely sensitive to light and are responsible to see light and motion. On the other hand cones give the color and require significantly brighter light. This explains why we do not see color in low light. Now, humans have only 3 types of cones to see red, blue and green color. Yes, all the other colors we see are the combination of these three colors. Most birds have 4 types of cones and see all the colors that humans see plus the ultraviolet part of the spectrum. The mantis shrimps are the best in color vision. They have 16 color receptive cones. They see colors that for us are even hard to imagine.

Mantis Shrimp, Photo: http://en.wikipedia.org/wiki/Mantis_shrimp

Mantis Shrimp, Photo: http://en.wikipedia.org/wiki/Mantis_shrimp

Now lets talk about night vision. Cats and dogs have 2 types of cones. So they see less color than human. But they have more rods and the low light performance of their eyes are extremely good. Cats have a special layer of cells in the back of their eyes that enable them to see at least 6 times better than us.

Here is a video by DNews on how animals see the world:

The birds of pray, like eagles have binocular vision like humans where both eyes continuously focus and work together to create an image. But, their long distance sight is so good that they can spot their pray from a distance of 3 kilometers.

Here is another video about animal vision. Watch the video. There are some animals with cool eyesight that I haven’t written about here but are discussed in this video.

Source:
1. Earth Unplugged
2. DNews
3. Wikipedia

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