It isn't' and they aren't.
Our eyes are limited to seeing a narrow spectrum. We cannot see ultraviolet light (bees can!), or infrared, or x-rays, microwaves, gamma rays, or the whole majority of the spectrum. Se we don't see reality for what it is. Only partially.
But these are physical limitations. If we had bee's eyes we could see ultraviolet light and communications from flowers, for example. However, I'm not talking about physical limitations though. Our eyes - even within the boundaries of their limits - are not our windows to the world.
An experiment had been done on frogs' eyes.
It seems that frogs have eyes that have features in common with ours. They should be able to see as well as we do. However, micro electrodes implanted in the frog's eyes reveal that only select bits of information are being sent from the eye to the frog's brain. From the richness of our visual world, only very basic kinds of messages are being relayed to the frog.
"The frog does not seem to see or, at any rate is not concerned with the detail of stationary parts of the world around him. He will starve to death surrounded by food it it is not moving" J.Y. Lettvin, H.R. Maturana, W.S. McCulloch, and W.H. Pitts, "What the Frog's Eye Tells the Frog's Brain", chapter 7 in The Mind: Biological Approaches to Its Functions, William C. Corning and Martin Balaban,eds. (New York: Interscience Publishers, 1968), pg. 233-258The reality we perceive is not all there is out there. At least that's what the experiment of the frog's eyes suggest.
To honestly think what we see is reality is naive.
I wonder sometimes if we are much different from the frogs. Of all the information we have available, we simply do not take it all in. But we constantly make decisions based on the limited view we have of the world through they tiny slit we call reality. Ultimately, decisions must be made; we cannot go through life making none.
If a frog's eye shares features with our eye and what a frog is aware of is different than what it actually sees, it stands to reason that we may suffer the same.
Did you ever wonder why some things catch our attention more than others? Have you ever bought a new car? I have a Mazda 5. When I first got it I began to notice numerous Mazda 5's. They were everywhere! All of a sudden the world's filled with Mazda 5s. Of course, they were always there, I just wasn't noticing them.
Our sense are able to process only a narrow band of information that represents the visible and audible spectrum. This tiny opening we call "reality". It's a good think that there's a system filtering out information that apparently we don't need so that we are not overwhelmed.
Our eyes are not our windows to the world; our mind is. I don't just think it's possible, I know it is.
Here's an experiment. Give it a try! Think about hats today. Let your RAS show you all the hats out there you've been missing. See what happens.
So, if our (and our frog friends) eyes are not our windows to the world and reality; if the Reticular Activating System is a filter to our reality, and if our mind is the window to the world and the reality we perceive, it would seem to me that an emphasis be put towards making sure our minds are healthy, sober, and clear. That we put effort to purge confusion, illusion, and delusion. Because if our minds are inflicted with delusion, our entire perceived reality will be delusional.
How do we combat this delusion? How do we help the frog become aware of the still and silent food all around it?
We naturally notice things that interest us and are important to us. The RAS will pass through information even if it is remotely associated with what we hold as value.
As a person acts, so he becomes in life.
Those who do good become good;
those who do harm become bad.
Good deeds make one pure;
bad deeds make one impure.
We are said to be what our desire is.
As our desire is, so is our will.
As our will is, so are our acts.
As we act, so we become.
- Brihadaranyaka Upanishad
What is a priority to us literally shapes our perceived world. It literally becomes our reality. We must avoid allowing (willingly or not) confusion, denial, and delusion into our lives and minds. Beliefs are fine to have so long as we acknowledge them as such. When we mistaken our beliefs as facts we enter into delusion.
The Buddha said,
"We are what we think.All that we areArises with our thoughts.With our thoughts we make the worldSpeak or act with a pure mind -And happiness will follow you."From The Dhammapada, translated by Thomas Byrom, Vintage, 1996, Chapter 1