Floaters in the eye are caused by shrinking collagen fibers and gel in the vitreous humor, which can peel off the retina or form concretions.

“as we age those different fibers and gels shrink and contract and they peel off of the back of the retina so there's just in the middle now your your your eyeball doesn't shrink because it fills in with with fluid with saltwater basically but the gel part shrinks and as it shrinks and also pulls peels off the retina uh it can pull off kind of little tiny retinal bits not important to your vision bits but just like little tissue bits and also as it congeals it kind of uh can get little concretions in the jelly and we perceive those as floaters”