Strange visual symptoms, any ideas?

I have been experiencing strange visual symptoms lately (last few months) and wonder if anyone else experiences anything similar or has any ideas as to what it could be. I got an examination by an eye doctor who said my eyes check out as normal despite the fact that i see a lot of glare around bright lights at night (the rest of my vision is clear) i see double or "ghost" images especially around light sources, i also see trailers, cobweb like floaters, and prominent afterimages. Any ideas? I was thinking the source could be neurological but wouldn't my eye doctor have detected something like a potential brain tumor? So any ideas? Been researching alot on the internet and it's not due to headaches or anything like that. (I'm 21 and otherwise have perfectly normal vision and don't wear glasses).