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The Human Eye Has No Blind Spot

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There are approximately 8.5 million known species in the world. Each one sees differently. A few species’ vision is more advanced than others; as humans we are very limited to what we can see compared to other animals. Birds of prey have the ability to see extreme detail at far distances. A bee has hundreds of six-sided lens and together the lenses form a single image. And an octopus’s eye has no blind spot. Each of these species’ eyesight has evolved overtime to adapt to survival needs.

Most individuals take for granted their ability to see. Eyesight is a major connection to the outside world; around 80 percent of impressions are through sight, meaning that only 20 percent are from the other four senses. The human eye has evolved over time to turn into what it is today. Through human’s needs for survival, the eye has changed to suit humans. Two of the most common types of eyes found in nature are the camera-type eye and compound eyes; the human eye fits into camera-type eyes because just like a camera lens focuses light onto something, the eye does a similar thing. The cornea, a structure in the front of the eye, focuses light onto the retina, and behind the cornea, is a colored membrane called the iris. It has an adjustable circular opening, the pupil, which expands or contracts to determine the amount of light that enters the eye.

The eye did not always function this way. To get to this point the human eye has evolved. But scientist debate how the eye has evolved.

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