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.
It is thought that eyes were an evolutionary characteristic of the primal animals that evolved during the Cambrian explosion. A few million years after, eyes are today the most unifying characteristic of all animals, which serves to prove their utility. However, this organ of the utmost importance is incredibly sensitive and it susceptible to many kinds of damage.
Eyes in all animals differ in the way they are protected. In humans, this protection is threefold: firstly, the eyelids protect and water the eye. Secondly, the soft eyeball is situated in a resistant shell made of bone. Thirdly, a membrane surrounds it to protect it from outside influences. It is only natural that the human body has evolved to preserve the eye as much as possible. Therefore, people should also take extra care of their eyes so as not to lose the wonderful possibilities of eyesight.
Scientists have not thus far managed to build a device that will be able to replace the eye, regardless of how simple the process of seeing may seem when looked at first. The initial stages of seeing are, in fact simple, and consist of light detection, but the sophisticated interactions between the eye and the brain follow after, and researchers do not yet understand how these work.
An astounding fact about this amazing organ is that, amongst all animals, there is an incredible amount of types of eyes. In fact, there are 10 individual kinds of eyes, believed to have evolved separately from one another. In connection with the previously mentioned utility of sight, the fact that multiple organisms evolved eyes independently confirms the evolutionary importance of eyesight.
Human eyes can detect color, depth and direction to a reasonable degree, but there are birds that can see in UV. There are also microorganisms that have eyes that do nothing but distinguish light from dark. The mantis shrimp has hyper-spectral vision and probably possesses the most complex color vision system among all animals.
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.
It is thought that eyes were an evolutionary characteristic of the primal animals that evolved during the Cambrian explosion. A few million years after, eyes are today the most unifying characteristic of all animals, which serves to prove their utility. However, this organ of the utmost importance is incredibly sensitive and it susceptible to many kinds of damage.
Eyes in all animals differ in the way they are protected. In humans, this protection is threefold: firstly, the eyelids protect and water the eye. Secondly, the soft eyeball is situated in a resistant shell made of bone. Thirdly, a membrane surrounds it to protect it from outside influences. It is only natural that the human body has evolved to preserve the eye as much as possible. Therefore, people should also take extra care of their eyes so as not to lose the wonderful possibilities of eyesight.
Scientists have not thus far managed to build a device that will be able to replace the eye, regardless of how simple the process of seeing may seem when looked at first. The initial stages of seeing are, in fact simple, and consist of light detection, but the sophisticated interactions between the eye and the brain follow after, and researchers do not yet understand how these work.
An astounding fact about this amazing organ is that, amongst all animals, there is an incredible amount of types of eyes. In fact, there are 10 individual kinds of eyes, believed to have evolved separately from one another. In connection with the previously mentioned utility of sight, the fact that multiple organisms evolved eyes independently confirms the evolutionary importance of eyesight.
Human eyes can detect color, depth and direction to a reasonable degree, but there are birds that can see in UV. There are also microorganisms that have eyes that do nothing but distinguish light from dark. The mantis shrimp has hyper-spectral vision and probably possesses the most complex color vision system among all animals.
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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