Page 150 - The Miracle of Electricity in the Body

148 THE MIRACLE OF ELECTRICITY IN THE BODY

The wisdom behind the feeling of pain decreasing

during injury
Some people experience no pain when they are first injured and for
a while afterwards. Even though injured, these people can run away
from the danger or protect themselves. Sensations of pain are transmit-
ted by nerve cells, which contain a substance called “endorphin”, which
eliminates feelings of pain, aching and distress and relaxes the body.
Endorphin is literally a painkiller manufactured in the brain, secret-
ed at the time the pain is felt. Its effect wears off as soon as the initial cri-
sis has been overcome. In this way, even very serious injuries do not
cause violent pain sensations for a certain length of time. Painkilling
drugs function the same way. They do not actually treat most illnesses
or injuries, but are merely chemical substances that prevent us feeling
pain. The decrease in sensations of pain after an injury is another exam-
ple of God’s mercy on human beings.

The Transformation of Light Energy into Sight

Perception

The phenomenon of sight takes place gradually. Light particles
(photons) pass through the lens in front of the eye, are refracted, and fall
onto the retina at the rear of the eye as a reversed image. There, visual
stimuli are transformed into electrical signals and transmitted by the op-
tic nerves to a very small region in the rear part of the brain, known as
the visual center. After undergoing a series of processes, this electrical
signal is perceived in the brain as a visual image.
The two kinds of receptor cells in the eye are known as cone and
rod cells. Rods are so sensitive to light that they enable one to see even
under a pale light. However, in strong normal daylight, they become un-
able to transmit any signal. Cones, on the other hand, function in intense
bright conditions and enable images to be perceived in broad daylight.
When you look at a television screen, for instance, your optic nerve