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Ultraviolet Light Affects Skin

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Ultraviolet light surrounds us, but despite the fact that we cannot live without it, ultraviolet light can be very dangerous. It is common knowledge that ultraviolet light is damaging to skin, but it is often overlooked that it can damage the eyes. My science fair project is about how well sunglasses protect against different types of ultraviolet light using bacteria. I will test which type of ultraviolet light is more damaging to bacteria under a sunglass lens.I predict that the UVB rays will result in more bacterial colonies because with skin UVB rays do not deep and they only cause tanning which is not that significant, but UVA rays go deep in the skin and they cause skin cancer and can be very harmful.

Ultraviolet light is a type of invisible …show more content…

Light passes through the pupil and goes to the retina where rods and cones process the image and send it through the optic nerve to the brain. In order from the front to the back of the eye the conjunctiva is the first layer of the eye(Thompson, 2008). The conjunctiva is a translucent mucous membrane that covers the eye. It lines the eyelids and covers the front of the eye. It is the outer protective layer of the eye. The eyelid conjunctiva and the eye conjunctiva glide over each other to make blinking and other movements more comfortable (Fekrat, 2005, p.1-8). The sclera is the tough, white, outer layer of the eye. It starts at the edge of the cornea and wraps around the eye until it reaches the optic nerve. The sclera is composed of tightly woven fibers that protect the eye from getting damaged and help it hold its spherical shape. Eye movement is controlled by six muscles that are attached at various points on the sclera (Fekrat, 2005, p.1-8). The cornea is a translucent, round layer in the front of the eye. Light travels through it to enter the eye. It is composed of five transpicuous tissue layers. The cornea does not have a blood supply, unlike most of the eye. It contains tiny nerves which make it sensitive to pain (Fekrat, 2005, …show more content…

The cornea does 70% of the light bending and the lens does the other 30%. The lens is located behind the iris. It is suspended in a capsular bag by zonule fibers (Fekrat, 2005, p.1-8). The vitreous is a gel-like layer in the vitreous cavity of the eye. It occupies 80% of the eye. The vitreous is composed of 99% water and 1% protein. It is attached to the retina in several places. The gel in the vitreous breaks down as a person ages (Fekrat, 2005, p.1-8). The retina is the innermost layer of the eye. It is a thin, multiplex nerve tissue that lines the back of the eye. It is located between the vitreous humor and choroid. The retina is composed of ten cell layers. It contains rods and cones which are photoreceptors. The macula is the central area for detailed vision. Rods function in dim light and cannot detect color. Rods are the first to detect movement. There are approximately 126 million rods in each eye. Rods are more concentrated in the center of the retina. Cones provide detailed vision and work in bright light for the best performance. They provide color vision. Cones are concentrated at the center of the retina (Fekrat, 2005,

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