The floating squiggled line(s) which sometimes show up without warning within the field of vision of an observer, unexpectedly occur when the vitreous gel-like substance of the eye helping it maintain a round shape, slowly shrinks. This substance fills approximately 80% of the eyeball itself. As the substance shrinks, it becomes somewhat stranded, and these strands can cast tiny shadows on the retina causing the observer to see floating squiggled lines
