the world > physical sensation > sight and vision > thing seen > optical illusion > [verb (intransitive)] > swim before eyes (3)
To move, or appear to move, as if gliding or floating on water; esp. to move, glide, or be suspended in the air or ether, occasionally by mechanical…
figurative, esp. with sense: to move or hover dimly before the eye or in the mind; also of a rumour, etc.: to pass from mouth to mouth.