Eyes are the most valuable and attractive body part of a human being. They make one’s life bright, colourful and meaningful. Without eyes life will be deep dark, sick and meaningless. No other organ in the body can equal the eye. Not larger than a ping-pong ball, the eye has millions of electrical connections and can handle 1.5 million simultaneous messages. Eye gather 80 percent of knowledge one absorbs. It is like a miniature television camera, the biggest, costliest T.V. Camera ever made.
The the transparent front part of the eye- the cornea starts the seeing process by bending light rays into orderly patterns. Then there is the pupil-an adjustable gate way for light. It is closed in the bright sun and is wide open on a dark night. The lens - a little envelope of fluid the size and shape of an oval vitamin pill is the most important part. The lens is surrounded by a ring of tiny, superbly strong, hard working muscles. When the muscles tense, the lens fattens for near vision; when relax, it fattens for distant.
Infront and behind the lens have two fluid-filled chambers. In front the fluid is like water, in back it is about the consistency of egg white. The watery fluid keeps the eye firmly inflated. The retina- a kind of onion skin wallpaper covers the rear two thirds of the interior of the eye. The light that passes through the lens gets correct focus on the retina. The retina covering less than 3 square cms contains 137 million light - sensitive receptor cells; 130 million shaped like rods lair black and white vision and 7 million shaped like cones for colour vision.
The rods are scattered all over the retina. The faint light bleaches a purplish red pigment in the rods which generates a tiny wisp of electricity. This feeds into the straw size optic nerve and is transmitted to the brain at about 450 km per hour. The brain interprets the signal and gives verdict in about 0.002 second.
The cones are concentrated in the fovea a pinhead size, yellowish depression at the rear of eye chamber. This is the centre for acute vision-reading, close work and for colour. The cones have bleachable colour pigments which are blended by the brain.
At the age of 6, our vision becomes excellent and at the age of 8 comes the peak sight. The eye moves about 1, 00,000 times to bring objects into sharp focus. The cleaning equipment of the eye, the lacrimal glands produces a steady stream of moisture - tears to flush away dust and other foreign material. The eyelids, act as wind-shield wipers. The tear contains a potent microkiller comed lysozyme, which guards the eye from infective bacteria.
Nature has given the eye a superb protection, placing it in a bony cavern with protruding cheekbones and forehead. They act as shock absorbers for direct blows. It has also the super sensitive nerves to alarm if there is a sudden damaging intruder like a cinder.
Hence, it is most justified to call it the greatest of all miracles.