Losing one's eyesight is the same as losing a navigator through the world. This is because this front sight organs are of vital importance for all living organisms. There have been many evolutionary steps to ensure that living beings are able to see in the best possible way.
Eyes are believed by scientists to have evolved at about the same time as the first animals (during the Cambrian explosion) in one species and within a few million years had spread to most of the others. No other sense organ is more common among the animals, probably a measure of the eye's utility. With the eyes usefulness also comes it's vulnerability due to it being constructed of mostly soft tissue.
While evolution has led the human body to evolve different means of protection, these can be separated into three layers: the most outer layer is the skin eyelid that covers the eye and also waters it. The second layer is the membrane that surrounds the soft tissue of the eyeball. And the remaining layer is the cavity made of bone in which the eyeball resides. Such highly developed mechanisms are a clear indication that eyes should be well taken care of.
Explaining the basic working principle of the eye is simple, despite this, human beings are yet to create a device that even comes close to matching the eye's function. This is because the light is not simply a light detector, but does what it does through a complex interaction with the brain. In fact, it would take a powerful super computer to model the visual cortex on it's own.
In favor of the claim that the eye is one of the most important sense organs in all organisms is the fact that there are more than 10 distinctive kinds of eyes present among various animal species. On top of that, it is believed that these evolved independently from each other. The fact that it is not just a few organisms that recognized the evolutionary importance of eyes, but ten different once, underlines the claim that eyes are of such great importance.
The human eye, in fact, is very limited, as it can only differentiate and perceive colors, depth and direction to a certain degree. Some animals have much greater sight, like some birds that can detect ultraviolet, or the mantis shrimp that has hyper-spectral vision. On the other hand, there are less evolved organisms whose eyesight is very basic. Some microorganisms' eyes only serve to differentiate between light and dark.
The functioning principle behind a camera, telescope, microscope or any other light-focusing device is the same as the one in the human eye. Once light enters the iris, it is focused in the direction of a small patch of photosensitive cells. The iris can be expanded or shrunk to increase or limit the amount of light that enters the eye. While the initial stage does not differ, what follows afterwards is radically different and undeniably more complicated.
The previously described phenomenon is just one part of eyesight. While that one is relatively simple, it is what follows that baffles scientists till this day and yet has no explanation. How is it that the eye communicates with the brain in order to create an image from light-focused photons? Even if there is still no clear answer to this, one thing is well known: a world without sight would be a world without light, and to preserve the gift of eyesight, one must take extensive care of their eyes.
Eyes are believed by scientists to have evolved at about the same time as the first animals (during the Cambrian explosion) in one species and within a few million years had spread to most of the others. No other sense organ is more common among the animals, probably a measure of the eye's utility. With the eyes usefulness also comes it's vulnerability due to it being constructed of mostly soft tissue.
While evolution has led the human body to evolve different means of protection, these can be separated into three layers: the most outer layer is the skin eyelid that covers the eye and also waters it. The second layer is the membrane that surrounds the soft tissue of the eyeball. And the remaining layer is the cavity made of bone in which the eyeball resides. Such highly developed mechanisms are a clear indication that eyes should be well taken care of.
Explaining the basic working principle of the eye is simple, despite this, human beings are yet to create a device that even comes close to matching the eye's function. This is because the light is not simply a light detector, but does what it does through a complex interaction with the brain. In fact, it would take a powerful super computer to model the visual cortex on it's own.
In favor of the claim that the eye is one of the most important sense organs in all organisms is the fact that there are more than 10 distinctive kinds of eyes present among various animal species. On top of that, it is believed that these evolved independently from each other. The fact that it is not just a few organisms that recognized the evolutionary importance of eyes, but ten different once, underlines the claim that eyes are of such great importance.
The human eye, in fact, is very limited, as it can only differentiate and perceive colors, depth and direction to a certain degree. Some animals have much greater sight, like some birds that can detect ultraviolet, or the mantis shrimp that has hyper-spectral vision. On the other hand, there are less evolved organisms whose eyesight is very basic. Some microorganisms' eyes only serve to differentiate between light and dark.
The functioning principle behind a camera, telescope, microscope or any other light-focusing device is the same as the one in the human eye. Once light enters the iris, it is focused in the direction of a small patch of photosensitive cells. The iris can be expanded or shrunk to increase or limit the amount of light that enters the eye. While the initial stage does not differ, what follows afterwards is radically different and undeniably more complicated.
The previously described phenomenon is just one part of eyesight. While that one is relatively simple, it is what follows that baffles scientists till this day and yet has no explanation. How is it that the eye communicates with the brain in order to create an image from light-focused photons? Even if there is still no clear answer to this, one thing is well known: a world without sight would be a world without light, and to preserve the gift of eyesight, one must take extensive care of their eyes.
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