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Warm-Up 2/29/2012 Name three ways in which you protect your eyes naturally. Characteristics of Your Eye. An adult eye measures between one inch in diameter It’s a hollow sphere Its filled with humors to maintain its shape Has a wall that is composed of three layers.
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Warm-Up 2/29/2012 Name three ways in which you protect your eyes naturally.
Characteristics of Your Eye • An adult eye measures between one inch in diameter • It’s a hollow sphere • Its filled with humors to maintain its shape • Has a wall that is composed of three layers
Cornea: “window”, crystal clear; where light enters the eye • Incorporates many pain fibers • Most exposed and vulnerable to damage, but has the ability to repair itself • It’s the only tissue in the body that can be transplanted from one person to another without worry of rejection
Choroid: blood rich region that is darkly pigmented • pigment prevents light from scattering inside the eye
Ciliary Body: tissue in the anterior portion of the eye that produces aqueous humor
CiliaryZonule: ligament that attaches the lens to the ciliary body
Iris: pigmented, acts as the diaphragm of the eye • Regulates the amount of light that enters the eye so that we can see clearly
Retina: light sensitive and contains rods and cones - Responsible for low intensity light; decrease in number as they reach the center of the retina/ peripheral vision PHOTORECEPTORS - Responsible for seeing color under bright light, densest at the center of the retina and decrease in number toward the edge. **Both respond to light**
Optic Nerve Transports nerve impulses from the eye to the optic cortex that eventually result in vision.
Photoreceptor cells are distributed over the entire retina, except where the optic nerve leaves the eyeball; this is called the blind spot/optic disc
Fovea centralis Lateral to each blind spot A tiny pit that is filled with cones This is where you have the greatest visual acuity (point of sharpest vision)