This is a good site:
http://www.gmu.edu/resources/facstaff/facultyfacts/1-2/
Tip? When you breathe you can see the air in front of your eyes cause distortions in tight patterns on objects in front of you. Like walls or the carpet.
With your imagination you can cause these shadows to grow and muscles around your occular lens can make the center of your vision magnify.
You can recognize a permanent pattern behind the movement, probably a tessellation of animals.
In areas where you lose vision completely you will see the void replaced by hallucinations. They will not have any sense to them, just pop in there. They may even be moving things like cartoons. Texts can appear that you can read, colors can change, etc.
You can extend these patterns and changes from single objects to your entire vision field and even your body. There really is no difference, it is all part of your perception.
You can feel with your body the Mouton's cookies, they can become emotions, this is called synesthesia and when you hit them they bounce and ripple.
The remarkable thing is that you can experience much of the basic phenomena without acid. There are separate physical explanations for what you see, but you get it all together with LSD. You will feel stimulated.
Your eyes naturally shake and that stops you from going temporarily blind. If you stare straight at something it can disappear, develop a halo around it, you can interrupt your vision with mental images, anything you can think of.
The real trick is how it affects your perception of things. You forget common sense and start to imagine reasons for things that are happening. Like paranoid thoughts, feelings of God like power, that you know more than you should about things. You may believe things about yourself that are nonsense. All these affects can come together to form complex delusions that seem to make perfect sense.
Your sense of who you are can become altered, you may realize what you thought was you and your world are just impressions your mind creates to represent what you are and they are not concrete truths.
Things you generally rely on for guidance, like taking to others, reading things, being secure in what you are experiencing are not there for you and you must rely on your own thinking to figure out what time it is, who you are, who other people are. It is like relearning what you know/are to find reality.
Or you could just have someone explain ask that to you and skip ahead to dealing with reality in the first place.
