When we are born the vitreous in the back of the eye is a gel (like jello just out of refrigerator). As we age it liquifies like Jello left at room temperature (the process is called syneresis). liquid vitreous collects in the gel (fluid pockets). You don't see the pockets but if protein or debris is in them they produce "floaters" There is not good treatment for floaters. Heavy duty surgery carries unacceptable risk and lasers have proved unsatisfactory.