What exactly is the viscous gel for in the eyeball?
Baby is right about the purpose of vitreous. However, vitreous is not constantly being produced and drained away. The thing that is constantly being produced and drained away is aqueous. More produced than drains away and you have glaucoma. The vitreous does not stay a gel all your life. Some time in your fifties or sixties, it turns to liquid. When it does, it becomes less stable and the membrane around it collapses causing an increase in floaters.