The most accurate depiction of drugs I've seen in the media is Vincent's heroin use in Pulp Fiction. Vincent does not suddenly become a dopefiend, nor is he slumped over or incomprehensible. He actually seems to enjoy it and almost functions normally. I don't use or suggest using heroin, but this serves as a good example of the common usage of that particular drug. This page is meant to serve as a more accurate report of how an Acid trip is like, though it really does it no justice whatsoever. These effects are shared by almost every other psychedelic, for example: Psilocybin (magic mushrooms), mescaline, and 2C-I.
This is how this scene would look to you sober. There is a lot of detail and external stimuli around your palm. You know your palm well, so if you aren't actively focusing on it, it isn't given much attention by your brain (hence the blur) as the seemingly overwhelming and new (and so possibly more dangerous) stimuli around you.
The acid is starting to kick in. Your pupils are dilating, making everything look a little clearer, with colors and lights being more vibrant. You also hear more and your ability to give attention to specific stimuli while ignore others is decreasing. You notice you are being more in tuned with the present moment in terms of what thoughts are going through your head and what you are paying attention to..
You're tripping. You look around and notice how many different things are happening. Not just in your view, but also within every object, and within that as well. A car may have a rust on it, and this suddenly makes you realize that cars are objects composing of atoms that are themselves always in motion. Chemical reactions are occuring all the time, in everything around you.
You realize that the palm you've taken for granted your entire life contains 27 bones and helps you physically manipulate your environment with astounding precision. You have opposable thumbs, 2 of them. Your hands can keenly sense heat and touch and your brain handles and reacts to this stimuli almost in realtime (in a general sense of time).
You're still aware of everything around you, but your mind is no longer filtering out extranous stimuli--the stuff you normally take for granted. With the filters off, every sense feels like is being bombarded with external stimuli, even though this is something happening all the time.
Your brain begins to react to every stimuli by finding every pattern (memory) it can for every stimuli you're focusing on in your head. These patterns are pulled up and gone through in your head to determine whether the stimuli is dangerous to you or not, and how you should react to it. Some stimuli (especially smells) will bring back memories that you've forgotten from your early childhood.
If you focus on a taxi, you begin to see how shiny a car's body is, how impressive the automobile is, things about the cab driver and humans in general (I usually see humans being just another animal but in clothing, which looks as ridiculous in my head at the time as seeing horses and cats wearing suits and dresses.) Your attention changes as quickly as your focus. It can be overwhelming the first time, but trips after this are easier to control and you aren't as couch bound by sights and sounds and your very distorted sense of time and space.
In your head, it almost feels like you can sort through every memory you associate with a specific stimuli, spidering out from one memory to another endlessly or jump from one stimuli to another as if you have ADD. This is why the stereotypical acidhead is sitting with dilated pupils in awe at this own palm or at the wall (where you notice every little smudge, crack and how rough the texture usually is.)