Importance Of The Front Sight As A Navigator
Without their eyes, most people would be completely lost, they are a means of navigating the world visually and are vitally important for all living organisms. Seeing is essentially, and the eyes have evolved some clever front sight formation methods in order to give humans the best picture of their world. Without this helpful organ, people would truly be in the dark ages.
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.
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.
While the general functioning principle of the eye appears simple, human capacity has not gotten as far as creating a machine that can perform the role of the eye. The complexity of the eye lies in the fact that it is not merely a detector of light, but carries out all its functions by interacting with the brain in an intricate manner.
One of the most surprising things you would find if you were to do a survey of sight and sight organs among all the animals is the range of eyes that are out there. There are believed to be more than 10 distinct kinds of eyes existing in nature currently, some having evolved independently of each other. This goes back to the earlier point about the evolutionary utility of sight.
The type of sight animals and organisms possess is suited to their evolutionary needs. While some microorganisms possess eyes powerful enough only to distinguish between light and dark, some birds are even capable of seeing UV. Humans, for instance, have a moderately good ability to detect depth, color and direction, while the mantis shrimp's hyper-spectral vision is believed to be the most intricate system of color vision there is.
The human eye works along the same principle as the camera or any other light-focusing device. Light enters the iris and is focused towards a small patch of photosensitive cells at the back, which convert the photons to neural signals. The iris can contract or expand to limit or increase the amount of light entering the eye.
Things are relatively simple before the light reaches the rods and cones (the light sensitive cells) but afterwards become appreciably more complex and as yet no convincing explanation of how people actually see has been put forward by the scientific community. The eye is a fascinating instrument and more still remains to be known about it. This is one reason why everyone must take every precaution to keep his or hers healthy, imagine losing such a wonderful gift!
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.
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.
While the general functioning principle of the eye appears simple, human capacity has not gotten as far as creating a machine that can perform the role of the eye. The complexity of the eye lies in the fact that it is not merely a detector of light, but carries out all its functions by interacting with the brain in an intricate manner.
One of the most surprising things you would find if you were to do a survey of sight and sight organs among all the animals is the range of eyes that are out there. There are believed to be more than 10 distinct kinds of eyes existing in nature currently, some having evolved independently of each other. This goes back to the earlier point about the evolutionary utility of sight.
The type of sight animals and organisms possess is suited to their evolutionary needs. While some microorganisms possess eyes powerful enough only to distinguish between light and dark, some birds are even capable of seeing UV. Humans, for instance, have a moderately good ability to detect depth, color and direction, while the mantis shrimp's hyper-spectral vision is believed to be the most intricate system of color vision there is.
The human eye works along the same principle as the camera or any other light-focusing device. Light enters the iris and is focused towards a small patch of photosensitive cells at the back, which convert the photons to neural signals. The iris can contract or expand to limit or increase the amount of light entering the eye.
Things are relatively simple before the light reaches the rods and cones (the light sensitive cells) but afterwards become appreciably more complex and as yet no convincing explanation of how people actually see has been put forward by the scientific community. The eye is a fascinating instrument and more still remains to be known about it. This is one reason why everyone must take every precaution to keep his or hers healthy, imagine losing such a wonderful gift!