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CARING FOR YOUR EYES AND EARS. Structure Of the Eye. Your eyes tell you about the world – about shapes, colors, and movements. Your brain interprets the data gathered by your eyes.
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Structure Of the Eye • Your eyes tell you about the world – about shapes, colors, and movements. Your brain interprets the data gathered by your eyes. • The eye works a lot like a camera. It takes in light and focuses it to create an image. The image is then sent to your brain, where the picture is “developed”.
Structure of the Eye • The optic nerve is a bundle of nerve fibers that sends messages to the brain, which interprets them. • The sclera is the white of the eye. It covers and protects the whole eye, except for the front. • The cornea is the clear section that lets in light at the front of the eye.
The iris is the colored part of the eye. It controls the size of the pupil. • The pupil is the dark opening in the center of the iris. It grows larger in dim light and smaller in bright light, so that the right amount of light enters the eye. • The retina is the light-sensing part of the inner eye. • The lens focuses the light on the retina.
Eye Care • Here some eye care tips. • Make sure that you have enough light. Read and watch television in a well-lit room. If necessary, use a reading lamp. • Avoid light that is too bright. Sit at least 6 feet away from the television set. Don’t look directly at the sun or at any other bright light. When you are outside, wear sunglasses that protects against UVA and UVB rays.
Eye Care • Avoid rubbing your eyes. If anything gets into your eyes, rubbing them may scratch the cornea. Instead, rinse your eyes with cool, clean water. • Protect your eyes from injury. Wear protective gear when you play sports such as baseball and hockey. If you work with power tools or chemicals, wear protective glasses or goggles.
Eye Examinations • To make sure that your eyes are healthy, visit an eye care professional examinations. • An optometrist is a health care professional who is trained to examine the eyes for vision problems and to prescribe corrective lenses. • An ophthalmologist is a physician who specializes in the structure, functions, and diseases of the eye.
Common Vision Problems • Nearsightedness. A person who can see clearly only objects close to his or her eyes. • Farsightedness. A person can see only distant objects clearly. • Astigmatism, an eye condition in which images are distorted, causing objects to appear wavy or blurry.
Your Ears • Your ears allow you to hear, listen, and learn. They also help you keep your balance. • The outer ear or auricle is shaped like a cup to pick up sound waves, which travel through the external auditory canal. • In the middle ear, sound waves make the eardrum vibrate. The vibrations move the hammer, the anvil, and the stirrup. These bones carry the vibrations to the inner ear. • In the inner ear, the cochlea moves. Tiny hair cells lining the cochlea vibrate in response, sending electrical messages to the auditory nerve. These messages travel to the brain, which identifies the sound.
Other structures in the ear are not directly involved in hearing. The eustachiantube keeps air pressure equal on both sides of the eardrum. The semicircular canals are filled with fluid and tiny hair cells. These hair cells send messages through nerves to the brain, helping your body keep its balance. • Caring for your ears involves protecting them from loud sounds. • The unit for measuring the loudness of sound is the decibel. Normal conversation is about 60 decibels. Sounds over 125 decibels are loud enough to be painful. Lower levels of sound can also harm the ears if the sounds continue over a long period of time.
