When I Bend My Head Down, I Am Starting To

When I bend my head down, I am starting to see what appear to be like the equivalent of tiny fan-blade like movements in my upper line of vision. I initially noticed it prior to a migraine but now see them without headache. I had a recent eye exam and no abnormalities noted other than very early stage of cataracts. Any thoughts on what could be causing these movements in my line of vision? Thanks.