Is it things floating around or are you seeing a rainbow colored halo(ring) around things?
I sometimes have something like this happen to me also. Mine is usually a rainbow shape that will wonder through my vision and usually continue to for 15-20 mins. I asked my co-worker (she is the head Vet-tech at the animal hospital i work at and a nursing student) about what it could possibly be. I dont remember exactly what she told me but it was harmless. Something to do with the inside of the eye having some sort of substance, floating around (that causes the blur/distortion you see) until it is reabsorbed and disappears. Thats what I'm guessing you had happen also. Hope this helps!
It may be due to GLAUCOMA, its better to consult an optholmolgist.