Why do i get double vision and feel woozy after leaning my head back?

Circulation issue: The back of the neck contains the vertebral arteries, the blood supply to the back of the brain, hearing, balance and vision centers. Leaning your head back, if it consistently causes deficits in these functions might mean there is compromise to these arteries. You should see a neurologist to get started as this may be progressive and lead to permanent changes.