Welcome to Chancellor Eye Care

Introduction

There is no single accepted explanation for all illusions you will see here today. Most of them deal with perceptions in the brain we do not yet fully undertstand. Most of the illusions, however, have to do with the fact that the brain tries to make a 3-dimensional world out of these 2 dimensional slides. You will see what we mean as we get into the slides.

There are three links in the optical illusion chain. The illusion could occure in any of the three links:

1. Image to eye.
2. Eye to brain.
3. Brain processing.

The five illusions we see here today will play with the thrid link, the way our brain processes images. All perception is linked to memory. The brain tries to fit each visual stimulas into a pre-made mold from prior experiences. As we shall see, not all of these molds are correct when applied to a 2-dimensional slide.

Which line is longer? Both are the same length. An example of the Muller-Lyer
illusion.The cause of this is unkown, however believed to be an effect of saccadic eye
movements.The eyes move horizontally less to scan the top image, and the brain reads
the lesser eye movement as meaning that the line is shorter.

Do sides of a triangle appear to be bent? This is an example of the brain trying
to make 3-D world out of a 2-D slide. The circles make the brain think it is looking down
a long tube. Therefore the legs of the triangle touching the inner circles appear to be further
away from you than the outer points of the triangle.

Similar to number 2. Center origin of rays give illusion of depth, therefore horizontal
lines appear to bow relative to how close they are to center.

Is hat taller than it is wide? No, brain has tendency to overestimate vertical lines.
Mechanism or reason is unkown.

Is arch continuous? Yes, it only looks broken due to illusion. Called Pogendorff
illusion, Overlapping contours confuse the bain. Often seen in ancient battle
flags where arrow crosses under crest. The warriors understood the illusion
and would intentionally draw the arrow on one side of the crest off-line
with the other end of the arrow so that it would look straight. had they actually
drawn a straight arrow through the crest it would have looked like they were charging
into battle with broken arrows!





	Introduction There is no single accepted explanation for all illusions you will see here today. Most of them deal with perceptions in the brain we do not yet fully undertstand. Most of the illusions, however, have to do with the fact that the brain tries to make a 3-dimensional world out of these 2 dimensional slides. You will see what we mean as we get into the slides. There are three links in the optical illusion chain. The illusion could occure in any of the three links: 1. Image to eye. 2. Eye to brain. 3. Brain processing. The five illusions we see here today will play with the thrid link, the way our brain processes images. All perception is linked to memory. The brain tries to fit each visual stimulas into a pre-made mold from prior experiences. As we shall see, not all of these molds are correct when applied to a 2-dimensional slide. Which line is longer? Both are the same length. An example of the Muller-Lyer illusion.The cause of this is unkown, however believed to be an effect of saccadic eye movements.The eyes move horizontally less to scan the top image, and the brain reads the lesser eye movement as meaning that the line is shorter. Do sides of a triangle appear to be bent? This is an example of the brain trying to make 3-D world out of a 2-D slide. The circles make the brain think it is looking down a long tube. Therefore the legs of the triangle touching the inner circles appear to be further away from you than the outer points of the triangle. Similar to number 2. Center origin of rays give illusion of depth, therefore horizontal lines appear to bow relative to how close they are to center. Is hat taller than it is wide? No, brain has tendency to overestimate vertical lines. Mechanism or reason is unkown. Is arch continuous? Yes, it only looks broken due to illusion. Called Pogendorff illusion, Overlapping contours confuse the bain. Often seen in ancient battle flags where arrow crosses under crest. The warriors understood the illusion and would intentionally draw the arrow on one side of the crest off-line with the other end of the arrow so that it would look straight. had they actually drawn a straight arrow through the crest it would have looked like they were charging into battle with broken arrows!