Well, my vision use to blacken and I'd get dizzy when I got up to fast, every now and then. As of late though it has been getting worse and I am not even getting up fast. My vision just starts to black out and I get dizzy then bout ten to thirty seconds later I'm fine. Though sometime I do have to sit back down cause it just gets so bad. I'm a seventeen year old, things like this shouldn't be happening. My parents want me to see a doctor about it, but I'm a bit scared of what it is, or what is happening with my vision and in my brain. Can anyone help or give me advice..?