THE HUMAN EYE

              It's interesting if we can know at least little about our eye because the eye is one of the important organ of the body.With the eye we are able to view everything around us but their are also essential parts of the eye that makes it possible for the eye to perform it's role which are:
      The Ciliary Muscles : It support the lens and attach it to the wall of the eye .Due to their concentration and expansion  it alter the focal length of the lens changing it's shape.We are able to see both near and far object with ease with the aid of the ciliary muscles.
      The Cornea : it is the thick transparent bulge in the front of the eye.It serves as a protective covering in front of the lens and allows light into the eye.It also partly focuses the light entering the eye.
      The Aqeous humour : It is the transparent liquid between the cornea and the lens and the vitreous humour is a jelly-like liquid between the lens and the rest of the eyeball.These liquids serve mainly to keep the eye in it's spherical shape.
      Iris : It is the part which gives the colour of the eye.It has a tiny opening at its centre called the pupil which regulates the quantity of light entering the eye .The pupil looks black because the inner layer of the eye,the choroid, is black.
      The Crystalline lens : It focuses the light from the object on to the light sensitive retina.
      The Retina : The Image is formed on the retina which consist of the light sensitive nerve endings which are connected to the optic nerve.The optic nerve conveys the sensation of sight to the brain.
       The Yellow spot :  It is the most sensitive spot of the retina and also where the light entering the eye are usually brought to focus with the clearest image formed.
       The Blind spot : It is the exit of the optic nerve from the retina which is insensitive to light.
      Major optical system of the eye consists of the the cornea,the lens,the aqueous and the vitreous humour .The retinal transmits the impression created on it by this image to the brain through the optic nerve.The brain then interpretes the impressions.
       

            THINGS TO KNOW ABOUT THE HUMAN EYE

• Each eye weighs ¼ ounce, measures less than 1 inch in diameter, and is shaped like a slightly flattened ball.
•  We should never put anything in or near our eyes, unless we have a reason to use eye drops. We would only do that if our doctor or parent told us to use them.
• Blinking helps to wash tears over our eyeballs. That keeps them clean and moist. Also, if something is about to hit our eye, we will blink automatically.
• Our body has some natural protection for our eyes.
• Our eyelashes help to keep dirt out of our eyes. 
• Our eyebrows are made to keep sweat from running into our eyes.
• Our eyes are very important to us, and we must protect them. We don't want dirt, sand, splinters or even fingers to get in our eyes. We don't want our eyes to get scratched or poked. That could damage our sight!
• The study of the iris of the eye is called iridology.
• The shark cornea has been used in eye surgery, since its cornea is similar to a human cornea.
• The number one cause of blindness in adults in the United States is diabetes.
• The eyeball of a human weighs approximately 28 grams.
• The eye of a human can distinguish 500 shades of the gray.
• The cornea is the only living tissue in the human body that does not contain any blood vessels.
• The conjunctiva is a membrane that covers the human eye.
• Sailors once thought that wearing a gold earring would improve their eyesight.
• Research has indicated that a tie that is on too tight cam increase the risk of glaucoma in men.
• People generally read 25% slower from a computer screen compared to paper.
• Men are able to read fine print better than women can.
  In the United States, approximately 25,000 eye injuries occur that result in the person becoming totally blind.
• All babies are colour blind when they are born.
• A human eyeball weighs an ounce.
• If the lens in our eye doesn't work quite right, we can get glasses to help us see. Glasses have lenses in them that work with our eye's own lens to help us see better.
• Babies' eyes do not produce tears until the baby is approximately six to eight weeks old.
•  Choose polycarbonate lenses for eye wear and sun wear. They are strong, durable, and impact resistant.
• The reason why your nose gets runny when you are crying is because the tears from the eyes drain into the nose.
•  The most effective sunglasses provide at least 98 percent protection from both UVA and UVB rays.
• The most common injury caused by cosmetics is to the eye by a mascara wand.
• Some people start to sneeze if they are exposed to sunlight or have a light shined into their eye.
•  Your body protects your eyes. Bony sockets guard against impact; eyebrows provide shade; eyelids and eyelashes keep things out of eyes;and tear ducts moisten eyes.
• The highest recorded speed of a sneeze is 165 km per hour.
•  When using a computer, adjust the lighting and sit at least 20 inches away from the screen in order to reduce glare.
•  Smoking increases the risk of some eye diseases such as age-related macular degeneration and cataracts.
•  People sometimes have red eyes in photographs, especially those taken with a flash, due to the light that reflects off the blood vessels of the retina.
• It is impossible to sneeze with your eyes open.
• The space between your eyebrows is called the Glabella.
• Inside our eye, at the back, is a part called the "retina." On the retina are cells called "rods" and "cones." These rods and cones help us to see colors and light.
• Just behind the pupil is a lens. It is round and flat. It is thicker toward the middle.
• Over the front of our eye is a clear covering called the "conjunctiva."
•  One in every 12 males is color blind. Color blind does not mean you see in black and white, but that you have trouble telling the difference between certain colors.
• The white part of our eye is called the "sclera." At the front, the sclera becomes clear and is called the"cornea."
•  When you blink, you shut your eyes for 0.3 seconds. That’s a total of 30 minutes each day!
• Certain patterns confuse your eyes and brain, causing you to misjudge the size of a circle or the length of a line.
•  The retina is about the size of a postage stamp. It has 130 million light sensitive cells.
• Around the pupil is a colored muscle called the "iris." Our eyes may be BLUE, BROWN, GREEN, GRAY OR BLACK, because that is the color of the iris.
• Our eyes have many parts. The black part on the front of our eye is called the "pupil." It is really a little hole that opens into the back part of our eyes.
• Your eyes blinks over 10,000,000 times a year!
•  Your eye is always making tiny, jittery movements. Each time your eye moves, it receives new information. This continuous supply of new information helps you see images.
•  Around the world, an adult goes blind every five seconds and a child goes blind every minute.
• Light-sensitive cells in the retina include rods and cones. Rods let us see shape and movement. Cones combine the three main colors—red, blue, and green—to let us see thousands of colors.

              Now you see how important the human eye is very crucial for mankind,so take care of your and don't joke with it.It's too fragile to handle helplessly.