Problems with vision, seeing little sparklies and blind spots...?

i have the sparklies too, and a few blind spots...migranes too.........i get them when i go from a dimly lit place to a bright place quickly, if i get up too fast and such (the sparklies i mean) i don't know what exactly causes it, i did have a brain tumor a few years ago, but have the same issues before and after, i am however, a diabetic...which affects the vision. i've always umed that is why i get them...i also sometimes see clear floating bubbles...the same way the sparklies come