HUMAN EYE AN ELECTRICAL ORGAN

Dominion, Volume 32, Issue 148, 18 March 1939, Page 6 (Supplement)

HUMAN EYE AN ELECTRICAL ORGAN

What Medical Research Reveals

The electrical nature of the vital processes in the body is becoming better understood as scientists are succeeding in measuring and recording the electrical waves and potentials generated in the various organs. The most recent discovery is that the eye is an electrical organ. It acts as though it contains a miniature dynamo that maintains a charge on each eyeball. This charge has been measured and studied by Dr. Walter R. Miles, professor of psychology in the Institute of Human Relations, Yale University. Investigation of the electrical properties of the eye has revealed some interesting relations between it and certain diseases, and the way we act under some circumstances. The semicircular canals in the ear control our sense of balance, but the eyes are the organs through which we “take hold'of space” and get ourselves co-ordinated with an up-and-down position. Further investigations may reveal that it is through the delicate sensitivity of the eye that we get our sense of direction, a sense which is highly developed in homing pigeons and other birds that make long migration flights, and in many animals. While Professor Miles does not commit himself on the “space gripping” ability of the eyes beyond what may be observed in laboratory experiments, such as the actions of a whirling dancer in tossing her head to recover coordination quickly after a rapid rotary motion, other investigations have observed that there is an electrical factor in the ability of homing pigeons to find their way to a distant roost. The sense organ in which this ability is situated is unknown. The revelations concerning the electrical properties of the eye by Dr. Miles offer a hint that this ability of birds to travel in trackless space may be associated with the electrical charge on the eyes. And Dr. Harlan I’. Stetson, of the Massachusetts Institute of Technology, has observed that homing pigeons released near powerful radio stations become confused when they take to the air, and many of them are unable to reach their destinations. The rapidly moving radio waves, with their powerful fields, near the station,’ would develop electrical charges on the birds’ bodies which may neutralize the standing electrical charges on the birds’ eyes, and the electrical currents genet- 1 and magnetic fields of the earth.

There is only a minute electrical charge on the eye, but Dr. Miles has measured it accurately with the aid of sensitive electronic amplifiers. He has

done this without discomfort to the person studied, because no electrical connexions are made directly with the eye. Electrodes attached to very fine wires are placed on the skin near the eyes, am! the electrical currents gene rated by the eye movements are picked up and transmited to a radio amplifying tube. The electricity in the eye thus is measured iifethe same way as the electrical waves in the brain are picked up on the skin surface through the skull by Dr. Halowell Davis at Harvard Medical School. There is the same difference between the electricity in the brain as there is between direct currents, and alternating current. The electricity in the brain is always pulsating, but the charge on the eye remains constant and manifests only when the eye moves. The lens part of the eyeball has a positive potential, and the rear part, where the retina is situated, has a negative potential. Professor Miles has measured the potential in many persons, and found that the lens part has a positive potential of about one millivolt, or one one-thousandth of a volt, with an equal and opposite potential ou the back part. The highest potential observed was iu a woman, whose voltage was five times higher than the average. , It makes no difference whether the eyes are deep-set or bulging, so far as the electrical state is concerned.

That the electricity has its origin ia the eye and not in the surrounding tissues is demonstrated by the eases in which subjects lacked one eye. A boy who injured his eye to such an extent that it had to be removed and who is using a glass eye had a normal potential in the good eye and no potential from the glass eye. Like results were obtained in six like cases.

The eye connects directly with the brain through a relatively large nerve that enters the base of the brain andhas Internal connections in the cerebral hemispheres to the visual centres that" are situated on the surface of each lobe in its central portion. The electric currents that are picked up on the surface of the brain, however, do not travel along the optic nerves and manifest at the eyeball. The nature of the physiological activity within the eyeball that creates this potential is unknown, but it appears to remain in constant operation, varying only slightly in successive measurements. It maintains the charge on the eye against the moist, saline, short-circuiting tissues that surround the eyeball.