Light strikes the retina, activating photoreceptor rods and cones. Immediately, impulses discharge through a myriad of bipolar and ganglion cells, along fibers that gather in bundles of optic nerves and stream like two converging rivers to the chiasma, spreading from there to junctions beneath the brain. Here at the geniculate body, colors are sorted—blues, reds, and greens. From these junctions nerve fibers course to the visual cortex at the back of the brain for processing shape and form—flowers, grass, sky. The need for action blends with stored experience, the interpretive melding almost instantaneously. Move forward to smell, smile, proceed with caution, whatever it takes for motion or stillness, flight or rest. The eye, a complex machine beyond comprehension, has evolved through eons of hunger, hunt, fear, and survival.
Wiped out by a single bullet—rods and cones, branching neural connections, chemical end points. Capillary channels fill with coagulating plasma and stagnant, anoxic red cells. Ten-year-old eyes glazed, not by age or disease, cataracts or thrombosis, but by a round, metal projectile smashing through the skull or heart, shutting down the magnificent machines, forever. Presidents of the United States and members of Congress deem bullet and gun indispensable to the defense of the people, by the people, against the people. This, too, is the judgment of the President of the National Rifle Association.
The child standing at the street lamp views his world; cars, buses, and people stream by.
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Car. Careful, careful comes the caution from the cortical cells. Do not step off the pavement. Stored images of mother and teacher, wagging fingers. No, do not! The eyes absorb the curbstones, the feet stay put; tires sweep by. Mother and teacher will be pleased. The lips spread in a smile as the metal bullet intended for someone or no one, smashes through the skull. The child's eye machines gel. No more messages to the feet. No more tears flowing from the lacrimal glands to the puncta lacrimalia and into the ducts. The transparent corneas no longer need moisture. They dull in accordance with the laws of the land, of Presidents and the intent of Congress. In death the lenses behind each cornea swell.
There are 10 layers of cells in the retina, 7 million color-sensitive cones and 100 million light-sensitive rods. Bipolar neurons stretch from the rods and cones to the ganglion cells. Light sprayed with dark shadows from the streets of Washington, D.C., capital of the United States, passes through each lens to the retinas.
A 19-year-old man is fatally shot in South East Washington. The pupil, the aperture of the eye, restricts the amount of light passing through the lens. In the dark, the pupils dilate to allow the rods as much light as possible at 3:15 a.m. But the pupils also dilate because of fear, and pain, so the tense 19-year-old's pupils are dilated as widely as possible in the murky shadows, from fear and then, suddenly, from pain. At that very moment, in the early hours of the morning, with the nation at peace, the eyes of the sleeping Presidents are covered by eyelids, necessary to prevent desiccation. The surfaces of living eyes must always remain moist.
When will the first of the summer-weekend shooting deaths occur this year? Maybe on Friday at 10:55 p.m. as happened last year when police found a 26-year-old who later died in the hospital. Early Saturday morning, last year, after daybreak, police said a dispute resulted in gunfire. A young male from Ninth Street N.W. was shot several times. No one was arrested. At 3:00 p.m., Saturday, police responded to a reported shooting in S.E. Washington. This time, a Hispanic man was pronounced dead at the D.C. General Hospital. He was 48 years old and died of gunshot wounds. Early Sunday morning during a concert in Congress Heights, one teenager was shot dead and three others were wounded. An arrest was made, last year.
Light entering the eye is bent at four surfaces, at each surface of the cornea and at each surface of the lens, to converge on the retina and project an inverted image. Fibers pull on the elastic capsule of the lens to accommodate the image. The near point of accommodation, the closest point an object can be brought to the eye without distortion, must have been about 10 cm for the youngest of those shot dead in Washington.
Between 16 and 20 cm for the 48-year-old Hispanic man.
With age the lens hardens. Adjustments become more difficult. As the President ages he will not be able to read a book at 40 cm. True now for the other President—the one who heads the National Rifle Association. Older eyes require presbyopic correction by a convex lens. The frames fit snugly over the nose. Those other citizens, the ones dying in the streets of Washington D.C., won't be bothered by that expense.
The President of the United States, the most powerful democracy in the world, requires global vision. Nearer to home, however, his vision is more restricted. The past President of the United States was an avid golfer. His weak point was putting. He had a putting green built on the grounds of the White House. The image cast on the two retinas is two-dimensional. Positioning the three-dimensional golf ball and estimating the length it has to travel requires depth perception. To putt the ball he looks toward the hole. The lenses accommodate. Cortical cells compare the two images emanating from the eyes and estimate the distance to the hole. The putter moves back, then swiftly forward. The ball rolls into the hole. The new President jogs around the new White House jogging track set up just for him. He needs only to judge distance correctly. President Clinton's eyes take in the smiling reporters. He smiles.
A well-regulated Militia being necessary to the security of a Free State, the right of the people to keep and bear arms shall not be infringed.
Cells similar to the "near" and "far" cells of the cat are very sensitive to distances. These are called "disparity" cells, and they respond to stationary or moving stimuli at variable distances. For example, a 46-year-old man was killed and three young children were shot and wounded when a man in a car fired into a crowd of people in the 1300 block of Park Road N.W. The wounded were two girls, 7 and 11 years old, and a 4-year-old boy. The gunman fired the shots from a dark-colored car that sped away. Stimuli from the targets were coordinated and lined up instantly by disparity cells of the gunner in the dark moving car.
"Blood was pouring out of the girl's neck," said a man who ran to the scene. Poor man. Messages from the awkward, twisted shapes sped through the rapidly accommodating lenses as he came closer and closer to the bright red blood.
This year the disturbed mind in the Mount Pleasant area used a shotgun. He killed two persons and wounded several others. Perhaps the relatively poor shots, the unplanned survival of some targets, were related to what is known as stereoblindness, an inability to judge depth or distance correctly. The condition is relatively common, particularly when strabismus, failure of the eyes to work in parallel, goes undetected.
Even closing the eyes for prolonged periods does not result in permanent blindness. Thus, members of Congress can close their eyes for an entire Congressional session and not go blind, provided they remain alive and all body systems continue to function. When they ultimately lift their lids, all visual acuity is recovered within a short time. They can, in other words, go on with their games without losing any of the benefits of the protracted sleep.
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