I had this idea whilst walking in the woods today. I was looking at the leaves on the ground, and wondering how the brain could create such a level of detail in dreams - Such a high level of detail, in fact, that we do not realise we are dreaming.

And then my mind skipped back to a Biology essay that I had once had to write. It was basically about what are known as 'blind spots'. Look at the image below for a demo.



Close your left eye, and with the right eye, look at the square. Now, move your head closer and closer to the monitor. Did you see it? The circle dissapeared!

If you didn't see it, try again. I promise you that it does happen. Make sure that you never look at the circle; Always at the square. You'll see the circle out of the corner of your eye.

Now, this is because of the way that the eye is structured. Take a look at the diagram below:



See where it says 'blind spot' - where the optic nerve enters the eye? At that point, there is not one light-detecting nerve. It cannot see anything.

So, you may think: How come I never notice this? Surely I should just see a large black spot as I walk around?

Aha. Well, no. In fact, the brain is incredibly clever here. What it does, is it 'patches up' the spot. For example, above, the brain recognised that the red circle was surrounded by white. Therefore, it deduced that the area that it couldn't see - the red circle - would also be white. Neat, huh?

But that's not the end. Oh no.

Not only can the brain do this with colours; it can do it with patterns, too. If you're clever, you may be able to tell where this is headed.

If there was a grid around the circle, the brain would patch up the invisible area with a grid. If there were pink and blue alternating squares, it would patch it up with pink and blue alternating squares. And if for example, there were leaves surrounding the red circle... it would, of course, patch the area up with more leaves.

So, what I suggest is this: When the brain, in dreams, is creating patterns, it doesn't create every tiny little 'pixel' of light. It just creates what you may call a 'conceptual' pattern; the little 'patch up' section in your brain goes into overdrive. The only place that it doesn't do this is the direction you happen to be looking at, which, I believe, is the effect that everyone seems to describe in dreams: what you are focused on is crystal, but the things in the corner of your eye are blurry. This way, the brain can still create images realistic enough to trick you, but it also doesn't have to use up tonnes of energy in doing so.

What do you think?