Importance Of The Front Sight As A Navigator

By Ida Dorsey


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.

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.

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 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 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.

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!




About the Author:



No comments:

Post a Comment