I responded to your other post I believe, as well.
I was just about 19 years old when this started for me. I'm 22 now and I still have it - basically all the symptoms you described. From time to time I get worried about it, but I always assure myself that its not that uncommon. I've read about it, and lots of people have weird visual things, with no diagnosis for it, and no debilitating illness. I've mentioned it to three eye doctors now, and they all did a thorough exam and found nothing. I don't believe it is actually related to my eyes. I told the neurologist and she is sending me for a VEP (visual evoked potential). It tests your optic nerve or something. I decided that if this test is clear I will be done worrying about it for good! If something comes up during the test, then I'll take it from there.
Anyway, I wouldn't worry about what you're experiencing. You are young and theres a chance that you'll outgrow it maybe. I'll let you know if I find out anything good!