Tyrosine-kinase inhibitor's secondary effect (one of the many)

a tentative to describe one of the scariest things i experienced since i have leukemia on board :
suddenly, with no warning, a strange sensation coming from the back of the neck, like a black veil , instantly followed with double or triple vision for at least half an hour.
a more comon one is kind of stroboscopic black and white ribbons turning in my eyes, especially after a few hours working on my pics.