“The eye sees only what the mind is prepared to comprehend.”
–Henri Bergson French philosopher, 1927 Nobelist
Where the optic nerve enters the retina of the eye there is a blind spot that registers nothing. But the mind, the brain, makes up for this empty space by filling in what it thinks ought to be there, not what’s actually there, but what it creates. When seeing in low light there’s an additional blind spot, the Fovea Centralis, that is unable to see color and the objects that are seen are indistinct. As with the optic nerve the brain also fills in the fovea “blindness”.
Don’t believe the blind spot exists? Close your left eye and cast your right eye on the black “cross” sign of the figure below. Move your head close to the screen until the black dot on the right suddenly disappears. The “missing” information will be “patched in” using the surrounding parts of the picture and you see only a white area.
The brain also estimates the size of things by contrasting with surrounding objects. Ever notice how the moon looks at least twice the size when it first rises above the horizon than it does high in the sky? Actually they’re both the same size 1. Also if you were to stand in front of a mirror looking at your face, all looks normal or what you’re normally used to seeing, right? But have you noticed that regardless of how close you are the reflection is only half the size of your real head (measure the mirror image then your head)?
Notice the illusion below: Two different tables right? No, they are actually the same table if you measure them with a ruler.
The above illusion, moon, and mirrored face visuals are all a part of unconscious processes going on in our minds.
And every time we shift our visual attention, the attention of the mind shifts as well. This is part of the bag of tricks wielded by a magician, or even a con artist e.g. shifting your visual attention so as to do something outside your minds focus.
With only a few exceptions in so-called eye-witness testimony people are drastically affected by their level of stress i.e. efficiency of memory goes down with higher stress and then what was seen is stored into recall in a way that makes the most sense to the witness. This is highly dependent on past experiences and prejudices and/or social values. People often will add meaning to their observations that of course affects the observation. For example, the mind will often edit any puzzling or incongruent observations.
Most importantly, and more to the point of this article, what we see is determined by context. A simple proof of this is how we use visual context clues in order to read e.g. You and I can rad this sntnc vn though w hav lft out th ee’s.
Context is also what makes a movie, well… move. In reality it’s just 24 pictures shown per second that when the mind stitches them into a sequence makes it look as though something is moving. 2
But notice it’s not the context of the external reality that I am referring to. It’s our internal reality that provides the context for what it is we see.
And that brings me back to Bergson’s quote from the beginning of this article. What our minds are ready to comprehend is determined by our beliefs, our past experiences, our prejudices, and expectations. In short, our experience of reality is determined by something other than reality–we see what we believe, not the other way around as the popular quotation goes, “seeing is believing”.
Our mind is conditioned to seeing what it thinks that it should and anything outside that conditioning is just not seen.
In order to open ourselves to new possibilities we must first look at the contexts we have created to see what we are currently looking at. We might also be willing to question what it is we are seeing and what about our own minds may be affecting that vision.
So what really is reality?
Are you sure?
1See Emmert’s Law to explain this phenomenon http://en.wikipedia.org/wiki/Emmert’s_law
2 There are some theoretical physicists who have asked the question as to whether there is any movement other than several moments of time stitched by the mind into what appears to be a moving sequence.