Do You Know How The Human Eye Works?

What you are about to read is a comprehensive discourse of the marvel we call vision, the many problems which can beset your eyes and vision, how they can be alleviated, or made more tolerable. Learn more at
By: Bill Coughlin
Nov. 20, 2009 - PRLog -- You’ve probably heard it said that the eye works much like a camera. It focuses light to form images, and then converts those images into nerve impulses for the brain to interpret. This is similar to the way a camera lens transmits images to film.

The eyes are spheres about an inch in diameter, self lubricating, self cleaning, well protected, and so sensitive that they can distinguish between images only one ten thousandth of an inch apart. An eyeball is made up of several complex structures.

The Sclera, forms the round wall of the eyeball, the part we commonly refer to as the white of the eye.

The Cornea is a transparent, dome like window at the front of the eye. As light enters your eye, the cornea bends, or refracts the light before it passes through the lens.

The Iris is the part of the eye we refer to when we describe the color of the someone’s eyes. Typically a shade of brown or blue, the iris sits behind the cornea and acts like a curtain as it controls the amount of light entering the eye.

The Pupil is the black hole in the center of their iris that determines the amount of light entering the eye. In low light the muscles of the iris cause the pupil to open wide or dilate; likewise, the pupil constricts in bright light.

The Lens, which sits just behind the pupil, is really a flexible bag of clear protein that helps focus light onto your retina. Surrounded by a thin membrane called the capsule or capsular bag, the lens is shaped like a piece of M&M candy.

The Retina, lines the back half of your eyeball, about the size of a postage stamp and as thin as onion skin, the retina is the “film” of the camera. It registers light images and sends them to your brain through a bundle of nerve fibers called the optic nerve.

The cavity between the lens and the retina is filled with a transparent gel like substance called the vitreous humor, through which light rays pass from the lens to your retina. As this gel becomes more watery with are, tiny residual solid portions can move. This creates harmless drifting shadows know as floaters.

The surface of you eye is constantly lubricated by a steady production of tears, a marvelous process provided by nature. Tears flow from glands at the upper, corners of the eyes, and drain through tiny tear ducts in the inner corner of our upper and lower eyelids. When we blink, we pump tears from the eye surface into the tear duct drainage system.

This is why if we are about to cry, we start to blink more as our eyes are welling up with tears. Rapid blinking pumps the tears into the tear ducts.

The tear duct passes through channels within the bones of the nose and eventually empties the tears in the back of your throat. This also explains the otherwise puzzling phenomenon of being able to taste eye drops.

Don’t delay seeing your doctor if you experience a reduction in the clarity of your vision. The right diagnosis and proper treatment can protect your eyesight and preserve or improve your vision. Learn more at

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What we feed our bodies feeds our eyes. Many of the vitamins and minerals in our bodies are found in much higher concentrations in our eyes, so a diet lacking in these vitamins and minerals can lead to vision problems as we grow older.
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Tags:Protect Your Eyesight, Vision, Eyesight, Eyes, Eye Sight, Ocular
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