Optical illusions are occurrences in while images that are perceived by the eye are interpreted by the brain such that they are different from the objective reality.
Optical illusions can be divided into physiological illusions and cognitive illusions.
Physiological illusions are illusions that are the result of excessive or prolonged stimulation on the eyes and the brain of a specific type, such as brightness, tilt, colour, movement. Such illusions are created by taking advantage of the limitations of the human visual system
Such illusions are due to the limited number of neural pathways (nerve transmission pathways between the eyes and the brain). Repeated stimulation of the limited number of pathways leads to an optical illusion.
If you stare at the image for 1 minute and then look at a white background, you'll see the image being projected onto the background. This effect is called an afterimage.
There are also illusions that are caused by the difference in distributions of rod cells (sensitive to black and white) and cone cells (sensitive to colour) within the retina (the part of the eye that is sensitive to light and generates a nerve signal to the brain). This causes light to fall on different parts of the eye to stimulate different number of light-sensitive cells, causing the perception of different shades or colours. On top of that, prolonged stimulation of the retina may fatigue the retina, resulting in an optical illusion.
The Hermann grid illusion, in which grey dots can be seen appearing on the white circles
The spiral can be seen to be moving (full view) although it is actually static
Cognitive illusions are mainly due to the limitations of the human brain in perceiving and interpreting a particular stimulus. Given a particular stimulus, the brain has a tendency to interpret it in a particular way, according to our:
- Natural predisposition in judging perspective (height, width, depth, distance). For example, when we view a 10 cm stick that is close to us and a 1 m stick that is further away from us from a certain point. From our point of view, we may perceive both of them to have the same length, but we know that the distant object must be longer since it is further away.
- Learned knowledge. For instance, we see a rabbit in a line drawing because our knowledge tells us that it is a rabbit.
Cognitive illusions can be categorised into several types:
- Ambiguous illusions in which an image can be perceived in more than one way to yield equally valid results.
- Distorting illusions in which a perceived image is distorted in terms of size, length or curvature.
- Paradoxical illusions which offers objects that are impossible.
A young or old lady?
The Scroeder staircase. Are you viewing it from above or below?
The Necker cube. The front face of the cube changes depending on how you view it.
The two yellow lines have the same length. Our perspective tells us that the one further away from us is longer.
How many legs does the elephant have?
The Penrose triangle. The illusion is created by the assumption that adjacent edges must join together.
While optical illusions may be interesting, and perhaps even entertaining to us, there is a different kind of illusion that we are faced with every single day of our lives. We perceive all kinds of inputs from the world around us with our eyes and interpret those inputs with our minds.
We live in a world where all kinds of stimuli of control, common sense, comfort, cravings and convenience vie for our attention. These could well be, say a nice house, a good career, a position of authority, or a gourmet feast. We perceive them with our eyes and interpret it according to our minds, which are shaped by the tendencies of our natural beings and the knowledge that we gain. Most often, we find them desirable. We discover that they are pleasing to us. We allow ourselves to indulge in the satisfaction of these illusions that we miss the reality of things.
At the same time, we dwell in a world where all kinds of structures and man-made powers exist. Structures that are erected to control, powers founded upon man's knowledge of good and evil. The structures and powers gives us some degree of control over our lives and allows us to bring comfort and convenience into our world.
We live our lives happily in our illusionary world, until one day we soon discover that the previously delightful objects of our adoration do not satisfy the inner emptiness that grips us. We come to a point where the once delectable items of our worship no longer gives us the security or the comfort or the peace that it once offered. All the structures that are supposed to give us control are now controlling us instead. All the powers that we build to give us comfort and convenience crumble to the ground.
But why is that so?
The reason for that is because what we see and perceive are merely illusions of the true reality that they are.
The reality of things is this, that the Creator made the earth to be His temple palace and made man to be His image-bearers, ruling over His creation in relationship with Him.
However, the many illusions that are created by man's knowledge of good and evil continue to deceive us and lead us to believe in an illusionary world that is not of the Creator.
Just as physiological illusions arise from the limitations of our eyes, we are fooled by the illusions of this world due to the limitations of our human vision. Our visions are easily overwhelmed by the persistent stimulation and temptations of fleeting pleasures or structural giants. When we see the world around us through our human eyes, we see all kinds of structures and authorities, all sorts of pleasures and gratifications, all forms of successes and power. We are overwhelmed by the ubiquity and universality of these sights that we perceive them to be the reality of things. We fail to realise that the powers and structures that govern us now, are fleeting and ephemeral, that one day they will be destroyed by fire.
We are also limited by our human minds. Just as our minds have problems in discerning cognitive illusions due to our preponderance towards certain perspectives and due to our knowledge and learning, our minds also have difficulty in sifting out and distinguishing between illusion and reality.
Like ambiguous illusions, we live in a postmodern world that is characterised by relativity and the lack of absoluteness. We perceive the world as being filled with ambiguities and uncertainties. We are uncertain of our futures or our destinies. We lack the clarity and oneness of mind to be able to say that we have a purpose here on earth, that we are not merely existing but we are specially made to be a people of the Creator. We use our knowledge of good and evil to condemn, compare and categorise individuals according to what we believe is good or evil. We have the illusion that our judgements are the best.
Like distorting illusions, the structures and man-made powers of the world are like concentric circles around the square. They distort our view of the square by making it look crooked and distract us from seeing the true nature of the squares whose edges are really perfectly straight. The rigid dogma and structures that we continuously hold on to in our religion distort the perfect reality of the Creator's purposes and promises for this earth. Rather than seeing it as a place where life and goodness can flow, we see earth as a trash heap which God will soon destroy. Instead of participating with our Creator in rebuilding and renewing the world which we will inherit, we think of escaping to another world far far away.
Like paradoxical illusions, our disbelief towards the Creator and His purposes, promises and presence drives us to come up with alternate explanations, no matter how absurd or ludicrous they are, to explain our existence. We try Darwinian evolution, the many universe theory, the theory of everything, the steady state theory. But no matter what explanation we try to come up with, it falls short of the glorious creation narrative of the Bible and the wonderful purposes that God has designed us for.
So what hope is there left for us?
The only possible way for us to get around all these illusions is live by the Spirit.
The Spirit gives us new vision that goes beyond our previously limited human vision. Through the Spirit's eyes, we are no longer deceived by the pleasing temptations, or allured by the powers and structures of the world but we see past the deceptions of all the pleasures, control, comfort, convenience, powers and elements of this world.
The Spirit gives us a renewed mind. With our renewed mind, we no longer use our knowledge of good and evil to create an illusionary world according to what we perceive it should be. We no longer use our common sense to give us a false sense of control and security. Rather, we see the purposes of the Creator and the promises that He has for us. And when we see the reality of the Oneness of and holiness by which He has carried out His plans since the beginning of creation, we can't help but stand in awe of the infinite love and wisdom of our God.
The Spirit burns away all the distractions that hinder us from worshiping the One True God, the Holy One of Israel. The Spirit destroys all the ambiguities that have previously turned our attention away from Him. In the Spirit, there is no longer any doubt of the clarity and oneness of the purposes of our God in bringing life and goodness and grace into this earth.
The Spirit strips away all the distracting elements that obscure the perfection of God's promises. The Spirit removes all the circles that were previously around the square, that we can see the square as it is, perfect and unbent. God removes all the distractions of this world, our control, common sense, desire for comfort, cravings and conveniences, that we may see the perfectness of His ways, that we were created to be Sons of God, to rule and reign with Him and not merely surviving under the rule of the authority of man.
Also, the Spirit demolishes the foundations of all the paradoxical illusions that were previously erected, all the idols and images that were worshiped in place of the one true Creator. Through the eyes of the Spirit, we see the absurdity of any other reason for our existence except to bring glory to our Lord, to be raised as kings and priests to rule with Him and serve Him in His temple palace which is the earth.
It is only through the Spirit that we have the clarity and faith to believe that we were made for more than living out each day of our lives in a cycle of monotony and mundaneness. It is only through the eyes of the Spirit that we see the reality of things as they are, that our God reigns as the One True King. It is only through the mind of the Spirit that we perceive the world in the true beauty that it was originally created for. And with the mind of the Spirit, we have the clarity and faith to say that one day, God will definitely make all things new and His plans for this earth will be brought to perfection.
And all the illusions the we once thought we ruled over us suddenly doesn't seem so real anymore...in light of the magnificent reality of God's creation.