Seeins and stars HELP!?

about three weeks ago ive been noticing this. it starteed off like seeing things at corner of my eye like spots or a bug flying, then when i looked at the sky it was if i had bad reception.. there was sparkles and stars flashing everywhere. its goten really bad and now i can say when im at school every once in a while the spots can be big enough to cause a tiny blind spot, maybe the size of a bead. not too big. sometimes the spot is yellow, green, red, blue, sometimes its multiple colors. MOST of the time they are little sparklins and they dont stay they flash but a few times they stay a little. I went to the doc and they put me thru a neurological test (such as walk in straight line...etc) to see if i had maybe a tumor but i ped it all so we went to they eye doc and he said my retinas are perfectly fine, then i went back to the doctor and they scheduled a CT scan to see if there was a detatch,=ment in the optic nerve or tumor or something and results came back fine. i also was put thru multiple blood pressure tests and blood tests and my blood work is all normal as well. WHAT can it be? and also it seems things are shimmering. sometimes white thinggs have a blackish hazy shimmering look to it and black things have a whitish shimmereing haze. WHATS GOIN ON? and i going blind?