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Printed from https://www.writing.com/main/view_item/item_id/1990539-the-eye
by fraz
Rated: E · Essay · Scientific · #1990539
this is how the eye works

the eye

The eye is the most complex organ next to the brain. It never stops working even when people are asleep the eye is always on the go. Unlike other organs in your body, the eye doesn't take time to warm up. Even though the eye is very complex, it is also very sensitive and can be invaded by viruses and even dust particles. There are often diseases invading the eye.

There are 11 parts in the human eye known to man; the iris, cornea, pupil, lens, retina, fovea, macula, optic nerve, the vitreous gel, and the Dua's layer which is a newly discovered layer in the eye. Every part of the body has a purpose. The iris is a muscle that controls the pupil and also the pupil is a hole in the middle of the eye that expands and contracts to let in more or less light.The optic nerve sends images to the brain. The retina is filled with light sensitive cells called rods and cones are in the back of the eye.

Eyes have phenomenons such as the prisoner’s cinema which is when people are in complete darkness for a long period of time, prisoners will see light that is not there. That’s why they often will see humanoid figures. When someone gets hit hard in the head and they see stars there is a logical explanation for this. The eye has liquid that feels like jello and when you get hit in the head hard the jello like liquid moves and hits the walls of the eye and that is what causes the stars they see. The eye is very sensitive in many ways. This is why people will feel this way when they get hit hard in the head!



Certain pathogens such as optic neuritis can invade the eye and cause all kinds of problems like blurry vision, inaccurate depth perception, blind spots, or being completely blind. Optic neuritis is when the optic nerve swells and blocks all the signals coming from the rods and cones in the eye which causes color blindness in some cases. Another pathology is macular degeneration which is caused by eating habits and diabetes and causes blurry vision in your central point of view and it cannot be cured. Another pathogen is glaucoma which is an age related disease that destroys peripheral vision. this can be treated with eye drops.

The reason people get yearly checkups to the eye doctor is that if they have an eye condition the doctor will see it. People won't have any visible symptoms from their point of view but when the doctor looks inside of the eye he/she will see something wrong. That way people can prevent having disease or find out about it early.

An iphone 5 has at least 8 megapixels which is a great resolution for a phone camera. Your typical digital camera that you can buy at target is at least 11 megapixels, that is great for a good print out of a picture. A costly pro camera is 15 megapixels which is for professional photography and video. The eye, by far, has more megapixels than any man made object. The eye crushes the competition with 157 mp. This is why when you look at a beautiful flower or landscape and you take a picture and it doesn't turn out like what you remember.



Vision, which people take for granted, is an important function of your body. However; what if someone finds out that they have a blind spot in their eye? The blind spot is where the optic nerve connects to the retina, this spot can be found by holding the thumb in front of the face and closing one eye. Then move the thumb to the left and then move to the right until it disappears. This is where the optic nerve is. The optic nerve sends signals of light from the retina to the brain. The brain translates the signals and sends them back and thats how you see. If this nerve gets damaged, it is very hard for this to heal due to the sensitivity of this nerve. Even though doctors have been planning on making a working prosthetic eye and succeed in doing so, they still can't figure out how to instal it because the optic nerve will not adapt to the prosthetic. If the optic nerve gets severed it will not heal back together, because of it’s giant nerve cell.

People watching high definition movies could get headaches. For because the cameras have so much frame rate that movement will not cause blurr. In order to translate movement, your brain causes movement to be blurry. That is why when a hand across someones field of view or a race car is zooming past a person, it seems blurry and not clear. A high definition movie gets rid of the blurr, but is still showing movement. This is paradoxical to the brain because the brain cannot translate the movement. Your eyes say that there is movement but your brain say there isn't any movement at all. That is what causes headaches, the brain and eye are sending opposing signals to each other. So, if someone is having a headache while watching an hd movie, the cause is now known.

The retina is a part in the back of the eye that is also connecting to the optic nerve that is covered with cells called rods and cones. These rods and cones collect signals from color and shape. If there is something wrong with the optic nerve, the retina might detach. Since the optic nerve is so sensitive, it will not grow back because there are no duplicating cells to repair the damage. Symptoms of a damaged retina are flashes of light, bad depth perception, sudden color blindness, and loss of vision. If any of these symptoms are evident an eye doctor should be contacted .

Some people are born with two differently colored eyes. This condition is known as “Heterochromia.” Heterochromia is mostly congenital or is caused by a disease or an eye injury. Most cases of Heterochromia are hereditary. and these may be a congenital syndrome. Sometimes a great great grandpa that had Heterochromia and it may not show up in any other member of the family for generations, this means that it is also genetic. Most cases of Heterochromia at birth are genetic and unassociated with any other ocular or systemic abnormality. People with this condition tend to have lighter irises in one eye than the other.


People from “Second Vision” created a bionic eye that looks like a pair of glasses. The pair of glasses has a camera sensor that sends the images to a command box that clips to the users pants and sends the signals back to the glasses that wirelessly transfers the information to a chip that arranges an electrical impulse on the last of the retinal cells. Unfortunately, this implant will only work if the patient is diagnosed with retinitis pigmentosa which is almost like a tunnel vision that gets smaller and smaller until you only see darkness. The signals that the small chip receives only show in black and white to the patient and show only 6o bit pixels. Doctors are still trying to get the system to give a full picture and in color but are unsuccessful at this time.

Eight percent of the entire population of the earth has blue eyes. The reason why the eye is blue is not because it will reflect blue light it is because of the same reason the sky is blue. Interference in molecules reflect and scatter light just like the sky does and that is why people perceive the blue eye blue. People with brown eyes actually have blue eyes it is just brown on top of blue.with a specific laser eye surgery to get rid of the brown

Even though 80% of all eye problems are avoidable or curable they still can be very costly. Optic neuritis, though it is unknown how it is caused, is easily curable but causes a scar in the back of the eye and leaves behind retinal damage. If people are cured by optic neuritis they will still have blurry vision but low class glasses can help.There are some diseases that are not curable such as macular degeneration, that’s a creeping disease will take a while to detect after a few visits to the eye doctor.

The visual cortex is located in the back of the brain, and sends signals to the back of the eye with the optic nerve. The optic nerve goes to the back of the brain. If something obstructs this connection from the optic nerve to the brain, a person will go blind. This is why optic neuritis creates loss of vision or greatly reduces it. This is also why doctors have no optic nerve transplants because once it is gone, it is gone forever.

If people put a colored object, such as a colored pencil, they will be able to see it but won't be able to see what color it is because the cones at the back of the eye is light sensitive, can see shapes, and can detect color while the rods are able to see shapes but cannot see color.

The human eye is just like a video camera; it takes light in, translates it into an image and develops it in the brain. Most people don't know know the frame rate of the human eye, it turns out to be that there is a minimum but not a maximum. The minimum amount of frame rate is 30 frames per second. The reason why the minimum of the frame rate is 30 frames is because 30 is the base frame rate that is undetectable to the human eye without skipping.

Eye surgery is a very rigorous. Though the eye is a fast healer, it can still be permanently damaged with the simplest mistake. An eye doctor needs a steady hand in order not to damage the eye. The surgeon has only 2.5 cm to work with inside the eye that requires very small tools to do tiny cuts. The way the doctors go into the eye is not cutting into it to open it up. But actually cutting into it sideways. The tools they use is the size of a syringe used for flu shots or smaller. In order to keep the pressure in the eye the same so it doesn't collapse, they will replace the fluid a fast as they lose it.

The way the eye perceives color is when white light hits an object and all the colors are absorbed except one. The one that is not absorbed is the color that hits the eye and is absorbed into the rods of the eye. Light and color is hitting the retina and causes a chemical reaction in the brain that sends the signals back to the eye and is perceived as color and light.

When the human looks around it is focusing on multiple things at once. But what happens in between the trip from point A to point B? It turns out that the brain deletes or ignores that visual information being sent to the brain at that time. The reason for this is because the brain does not want to have life as a blur because, it would be confusing to the brain to comprehend this.

The eye is connected to the brain with so many thick nerves that scientist are debating if the eye is a part of the brain. The theory states that the nerves in the eye connect directly to the brain with no obstruction. Some of the scientist believe thats the reason the optic nerve will not grow back is because the brain does not grow back.

Though prosthetics and laser eye surgery are available, the eye can not be replaced with a working eye prosthetic. Doctors have found a way to make a fake eye that doesn't work at all, but it will make it less detectable to see if a person is blind or not. First the doctor will fill the empty eye socket with a quick drying gel and will smooth it out. Than the doctor will then paint different colors on it to match the color of the patient’s eye. They will then check to see if it will fit, if so the operation is a success.

When the eye contracts cancer, it is at great risk of being lost forever. The first sign of cancer is a white pupal. The person that has the cancer will not be able to detect the cancer because they can still see at this point. The only known way of getting rid of eye cancer is either radiation or getting rid of the eye itself. The cancer causes headaches and possibly loss of sight if not treated .

The rods and cones have special traits that allow humans to see in low light areas and in color. Rods are spectacular in low light areas, but can not detect color. This is why when people are in a dark area they only see in black and white. When there is light and color all around, the cones take action and will send chemical impulses through the optic nerve in unison. The colors that are sent to the brain through these chemical reactions are red, green, and blue. Certain chemical reactions together will create different colors that are visual to the human eye.

The rods and the cones can be deceived by stimulating them to a person's liking. While a person holding a lemon is on a computer screen, the lemon appears to be yellow to the person watching the computer screen but it is not. The way a human sees yellow light with the retinas is by them sending chemicals responsible for seeing red and green light (retinas will specialize in seeing red green and blue, mix them together and they got a new color).

In order to focus when there is something smaller or bigger than what is around is by changing the size of the lens so that they are smaller or thicker to bend the light in a certain way. The thicker the lens; the closer the object is to focus on, and the farther the object is the thinner the lens is.

Even though the eye is the most sensitive part of the body and also the most complex, it can be damaged in many ways. Most of the injuries are permanent and can severely affect a person’s life. Certain pathogens infect the eye and will damage the eye by attacking cells, and causing nerve damage. Certain parts of the eye have certain purposes like the lens will dilate according to the light that is required to hit the retina. The retina picks up light to send signals to the brain. Eye doctors have to have a steady hand in order to do surgery because if they slip up, it could cost the patient’s their sight, it is amazing how doctors do it. The Second Vision’s bionic eye is proof of innovation into the positive advantage creating things that will give sight to the blind. This probably the best thing that would happen to a blind person. To see lights that are not there like on the prisoners cinema would be very frightening. To see objects form from those lights would scare most people into paranoia. Even though scientist do not know how this is caused, they are still trying to figure out why this happens. It is easy for the brain to be fooled by the eye sending the wrong signals to it and translating as the wrong color. Though scientist have discovered most about the eye they still believe that there is more to learn about it.
© Copyright 2014 fraz (fraz206 at Writing.Com). All rights reserved.
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Printed from https://www.writing.com/main/view_item/item_id/1990539-the-eye