is there an explaination??

why would i see things that arent there....its like i can be watching tv or reading or brishing my teeth and i see something or some kind of movement from the corner of my eye....and when i turn to look there is nothing there...but the hair on the back of my neck stands straight up...what is this and how can i explain what it is?? i have not had any surgeries to my eyes, i dont drink, do any type of drugs...i kno im not hallucinating...

I think this is pretty normal, at least for me it is. I frequently see flashes/movement from the corner of my eyes. What is it? I can't even begin to speculate. A skeptic stance would say that it is miss-firings in the optic never or brain, or something to that effect. A "believer" stance might say that it is a shadow person/ spirit/ or something of that nature.
Hard to tell what is exactly going on. If it is happening a little too often please see a eye doctor as you might have problems.