"You've taught me
all I know about
guitar, music,
theory, the business,
and songwriting...
You've always
believed in me,
in every endeavor.
Thank you,
for everything.
And I really mean
everything.
You're awesome."
All three of the optical illusions create a pulsation that is the same as the shimmer I have described above. All of the patterns create a sense of movement from a phenomenon called optical distortion. In addition, the illusion in the middle is an impossible figure, and the sense of color from the figure on the bottom is likewise an illusion. Here is what Classic Optical Illusions has to say about the figure on the top. "Take a look at the way the design at [top] pulsates. When you look at anything too close to you, the muscles around your eyes pull into a spherical shape to get the words and pictures into focus. Because the lens of your eye isn't perfectly round, however, some parts of what you are looking at will be in focus, and others will look blurry. Normally, the differences in the clarity of your vision are on the outer edge of the object you are seeing, so you can still read the words and recognize the pictures. But in an illusion, such as this one - where all the lines come from different angles and meet at the center - it is impossible for you to focus clearly on all of it at once. Your eyes are always making tiny movements, no matter how hard you try. So the clear parts of the design and the blurry parts are constantly changing. This is called 'optical distortion', and it is what makes the picture seem to move, shimmer, swirl, or pulsate" (Brandreth et al, p. 60).
Perception
Why does the dyslexic student see the shimmer (present in text when he reads) as being similar to the pulsation in the optical illusions? My theory is that it is because disorientation and optical illusions are both perception issues. Any mind will seek out shapes and patterns; the visually oriented mind even more so. Dennis Coon defines perception as, "... the process of assembling sensations ('data' from the senses) into usable mental representations of the world... Perceptual organization may be thought of as a hypothesis held until evidence contradicts it. Perceptual organization shifts for ambiguous stimuli. Impossible figures resist stable organization altogether" (p. 129). The pattern recognition abilities of the picture thinker can make him prone to make errors in perception, i.e. disorientation, but can also allow him to see subtle patterns in data, in his surroundings, or in art (whether visual or aural) that an auditory-sequential thinker might miss.
Harry Turner, an artist who creates optical illusions, has this to say on the subject of perception, "We are not always aware of the extent to which lines in two dimensions deceive the eye (and mind). Think how you grasp a whole comic situation from the simple lines of a cartoon. The image that falls on the retina of the eye resembles a cartoon from which we try to interpret outside reality. Not surprisingly, we make mistakes. Richard Gregory [author of Eye and Brain: The Psychology of Seeing] has described perception as continuous problem solving, because there is never enough information from the eye alone to specify external objects - the brain has to call on memorized sensory data to read a host of non-optical qualities into the images that are triggered by light falling on the retina. Our perception is so dominated by visual stereotypes that, for much of the time, we tend to see what we expect to see. All these optical illusions exploit this capacity to complete images in the mind's eye on the basis of past experience, by stimulating the imagination to override the simple logic of two-dimensional graphics" (p. 7).
