I Get Somewhat Get Dizzy And Get Whiteouts After Doing

I get somewhat get dizzy and get whiteouts after doing work that requires the use of my back...vacuuming for instance or lifting a dishwasher. Last time I vacuumed my right eye became totally ''whiteout''. I lied down and it went away. But anytime I do work that requires the use of my back, I get somewhat dizzy. I do have a lower back problem and I had it for many years....it is progressively getting worse.