How the eye works
By Madhura 8F
Parts of the Eye
• The iris (the pigmented part)
• The cornea (a clear dome over the iris)
• The pupil (the black circular opening in the iris that lets light in)
• The sclera (the white part)
• The conjunctiva (a thin layer of tissue covering the front of the eye, except the cornea)How the eye works
Behind the iris and pupil is the lens, the lens helps to focus light on the back of the eye. Most of the eye is filled with a clear gel called vitreous. Light goes through the pupil and the lens to the back of the eye. The inside lining of the eye is covered by special light-sensing cells that are collectively called the retina. The retina converts light into electrical impulses. Behind the eye, the optic nerve carries the impulses to the brain. The macula is a small, sensitive area within the retina that gives vision. It is located in the center of the retina and contains the fovea, a small pit at the center of the macula that gives the clearest vision.
Eye infections
(crying is not a infection)
Cataract
Crying
Tear glands are small glands inside your upper eye lid. Their job is to make tears to keep the surface of your eyeball clean and moist, and help protect your eye from damage.
When you blink, your eyelids spread the tears over the surface of the eye. Small things that are on your eye wash into the corner of your eye next to your nose. Sometimes tears flow over your lower eyelid, but mostly the tears flow down a tiny tube at the edge of your lower eyelid, next to your nose. This tube carries the tears to the back of your nose.
Pink eye
It's a name that sounds scary, but this common eye problem typically is easily treated and can often be avoided if you do the right things. Anyone can get pink eye, but preschoolers, schoolchildren, college students, teachers and daycare workers are particularly at risk for the contagious types of pink eye because they are closer in contact with others in the classroom.
Eye colour
Eye colour is created by the amount and type of pigment in the iris. Multiple genes given from each parent determine a person’s eye colour. Human eye colour start with three genes, two are from your parents, and the third pair of genes stand for the most common colours — green, brown, and blue.