There's a black dot when i see fr. my left eye. my eye dr. said it will go by itself. it's been years now& there are now more black dots in my vision.

Takes a while: I am guessing that your ophthalmologist (not an optometrist i hope) evaluated your eye including a dilated retinal examination. Since nothing therapeutic was recommended, you are probably having changes with age in your vitreous, which commonly includes the development of floaters in the vision. The fluids move very slowly and it can take years for some spots to disappear.