In our previous article where we discussed the mind-boggling complexity of our eyes’ retinas. We learned about the ten separate layers of cells, but we did not elaborate on the intricacies of their creation. We also learned how the substance in the cone cells, called rhodopsin, is destroyed on exposure to light and then regenerated in the dark. We thus touched on the wisdom behind the existence of both night and day.

The destruction of rhodopsin is caused by the generation of electricity after its contact with light. This electric impulse is transmitted from cones and rods to either horizontal or bipolar (having two poles) cells. The section between these two different layers of cells is called the outer plexiform layer, where horizontal cells receive electric impulses from rods and cones, and carry them to neighboring bipolar cells. The horizontal cells are also charged with transmitting electricity horizontally between rod and cone cells. The signals make it possible for shapes to be carried to the central nervous system in an appropriate contrast. Other signals are blocked so that the borders of the place of contact with light can be clarified in the brain, which does not receive an excessive load of signals. If it were not for these cells, it would be harder to perceive borders because the line of difference between two different colors would not become clear.

Bipolar cells have two opposite poles. They are created as one of two types, in accordance with their functions: one amplifies generated electric impulses, while the other inhibits the transmission of excessive impulses from around the perceived object to the brain. Bipolar cells provide the contrast necessary for making borders clear. They make clear vision possible, and yet most people have never heard of this wondrous gift inside their retinas!

How is contrast enabled?

Thanks to an innate ability, our brain does not occupy itself with regions that have the same color or the same light. It will not be stimulated much if, for example, a wall is completely white or a car is bright red all over. If, however, there are other colors on the wall, say, a white moon or star on a red background, then there will be more stimulation in the brain. Suppose we place the shape of a crescent on the wall. The stimulated parts of the brain will lie along the sharp ends of the crescent, not in the inside or outside of it. The stimulation in the brain is less associated with non-contrasting regions than contrasts in view. The higher the contrast, i.e. the greater the difference between light and dark areas, the greater the degree of stimulation.

Amacrine cells in the inner plexiform layer of the retina enable horizontal transmission. There are up to 30 different types of these cells, and they carry out at least five to six functions. For instance, one type of Amacrine cell transmits electric impulses from cones and rods to bipolar cells, then to other Amacrine cells, then to ganglion cells, and finally to the brain.

Another type of Amacrine cell responds strongly to the onset of the visual signal, while another to its completion. One other type reveals the difference in light intensity regardless of direction, while still others respond to the movement of a light point in a certain direction in the retina, causing a perception in the brain as to the direction of the light.

Further research may reveal yet more functions. Amacrine cells might have such functions as regulating the intensity of electric impulses specific to each wavelength and generating different levels of impulses for moving or stationary objects.

The function of the ganglion cells in the innermost layer of the retina is to help ensure that the electric impulse generated and corrected in the retina is eventually transmitted to the brain. Three distinct ganglion cells are identified in the retina. These cells are represented with the letters W, X, and Y. W cells are assigned the task of transmitting signals from rod cells, which produce black and white visual signals in the dark. Making up about 40 percent of all ganglion cells, they have diameters of less than 10 micrometers and transmit signals at a speed of 8 m/sec. It is evident that these cells are assigned the task of perceiving objects in the dark as rough, vague shapes.

X cells, on the other hand, transmit electric impulses to the brain, creating precise color pictures of objects. Making up 55 percent of ganglion cells, they have midsize diameters (10-15 micrometers) and transmit signals at a speed of 14 m/sec.

The largest of ganglion cells (with diameters as long as 35 micrometers), Y cells are assigned the task of transmitting instant changes in sight. Making up only 5 percent of ganglion cells, they send signals at speeds of 50 m/sec.

Sending intense signals in split seconds, Y cells inform the central nervous system immediately in case of a threat or an unusual encounter. When our body or eyes face a threat, these cells help protect us by warning the brain to move away from the threat or close our eyelids rapidly. If it were not for these cells, we would not be able to reflexively close our eyes and thus protect them. It’s incredible to ponder how complex these systems are – and how perfectly they’ve been created.

Between layers of cells there also lie layers of network that house neurons and their connections (synapses). These cells too have subgroups trained to carry out specific tasks. All of these cells are built according to certain specifications so that they can transmit stimuli to the brain when they receive light. Extremely severe visual problems develop when even a single layer of these types of cells is missing. Every one of the layers in our eyes is immensely special, and it is hard to imagine them to have been randomly placed there. It should be born in mind that this article simply skipped numerous elements of the retina and their chemical functions. Taking the precise measurements and mechanisms into account, we can only feel greater awe and love in the face of the incredible art devoted to the creation.

The first article can be found at https://fountainmagazine.com/2018/issue-126-november-december-2018/retina-the-mind-boggler

While the shahadah, the testimony of faith, detaches one from finite and false masters, the salat, the ritual prayers, detaches one from worldly affairs, zakat, charitable alms, detaches the worshipper from the pangs of material wealth, and hajj, the pilgrimage, is a means of detachment from the burden of sins and racism or nationalism, and sawm, fasting, detaches the worshipper from physical desires and emotional impulses.

What appears to be a self-inflicted ordeal to some is really a profound human experience. Fasting addresses a fundamental weakness in the human self-the tendency to act on impulse. The constant exercise of willpower to refrain from eating, drinking or having sexual relations, even though the body is constantly sending impulses to the human self, means that the will is in control. Fasting is not just about staying hungry or thirsty; it is also a struggle to refrain from any destructive impulses of the human self. Prophet Muhammad, peace and blessings be upon him, remarked, “If one does not abandon lies and acting on lies while fasting, then God has no need for him to give up food and drink.” So the main outcome of fasting is the curbing of all physical impulses that do not originate consciously from the person. In this way, one’s absolute dependence on these desires and impulses is detached and transformed into a relative dependence and one is guided only by God, which leads the worshipper closer to God.

Therefore, the fundamental spiritual benefit of fasting is to exercise the willpower and to attain the self-control that we need for success in every part of our lives. Fasting consecutively for 30 days truly sharpens the willpower and makes self-control a habit; this is true to such an extent that at the end of Ramadan most people feel as if they are still fasting. The benefit of attaining such a razor-sharp willpower extends its positive impact to every part of human life. It is important to maintain this newly gained ability throughout the year until the next Ramadan. The Holy Prophet used to fast on Mondays and Thursdays every week outside of Ramadan. He recommended Muslims to do the same or come up with other formulae for regular fasting, although this was not made compulsory.

An interesting experiment was done in the 1960s at a preschool on the Stanford University campus when the ability of four-year olds to resist temptation was tested. A marshmallow was placed in a room and the children were told that they could have the marshmallow immediately, or if they waited until the tester had run an errand and returned, then they could have two marshmallows. Some children waited for two marshmallows, while others ate one immediately. These same children were followed over 14 years to see how they managed in life.

Those who had resisted temptation at four were now, as adolescents, more socially competent, personally effective, self-assertive, and better able to cope with the frustrations of life. The third or so who grabbed the marshmallow, however, tended to have fewer of these qualities and shared instead a relatively more troubled psychological portrait. Even more surprising, those who had waited patiently at four were far superior as students to those who acted on whim. Most astonishingly, they had dramatically higher scores on their SAT tests. There is perhaps no physiological skill more fundamental than resisting impulse. It is the root of all emotional self-control, since all emotions, by their very nature, lead to one or another impulse to act.1

Naturally how one is raised in childhood has a great bearing on the skill of self-control. If our parents do everything we want and bring us everything we ask for our self-control will be low. Fortunately, Islam’s practice of fasting can break this negative childhood conditioning.

Mehmet Ozalp is the Executive Officer of the Affinity Intercultural Foundation, Auburn, Australia. He is the author of 101 Questions About Islam.

Note

1. Coleman, Daniel, Emotional Intelligence, London: Bloomsbury, 1996, pp. 81-82.