Blindness

People's brain and eyes must work together well to see. Inside the eyes, there are Lens, Retina, Ciliary body, Pupil, Iris, Cornea, Optic Nerve, and Conjunctiva. This is how eyes work-Light must reflect off an object, pass through the Cornea, through the pupil, and the lens. The image is focused upside down on the Retina, Rod and Cone Cells, the "Photo Receptors" transmits the image to the brain via the optic nerve. The brain corrects the image and we see right side up.

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What causes it?
The first basic reason is something that happens really often around us-Accident. Whenever people use sharp objects such as knives, scissors, etc., if they don't be careful, and the sharpedge hits or points your eyes then there are possibility to get blind. The second thing is Cataracts and Glaucoma. They are type of diseases that mostly happens to older people. If Cataracts happens, than the lens of the eyes get foggy, and it turns to as seeing through the fog. Glaucoma is when the eyes get too much pressure and it harms the other nerves, and causes blind. There are people who are born to be blind. This situation is possible to happen when the babies are born with the optic nerve being disconnected with brain or if there are any disease that harmed the brain before they are born.

How is it Transmitted?
Blindness is an Non-infectious disease.

What are the Symptoms?
The basic symptom of blindness is that you can't see the objects or other stuffs, so it will be very uncomfortable to walk around, work, write, and all other stuffs that people do during their life.

How long do they last? Is it deadly? Can it be cured? If so, how? If not, anyway at least to treat it?
It depends on what made that person blind. Some blindness can be cured but some are deadly. For example, Cataracts. Today, the techniques of surgery had been developed. Cataracts can be cured by surgery. For the causes that can't be cured by surgery, at least they can eat many vitamin A food, and be careful of their eyes from sharp objects or anything that can cause blindness.

Bibliography:
What causes blindness: http://www.mcwdn.org/Blind/BlindnessCauses.html
How eyes work: http://kidshealth.org/kid/health_problems/sight/visual_impaired.html
Information bout Blindness: http://members.fortunecity.com/alice_cheung/blindness.html