Floaters are deposits of various size, shape, consistency, refractive index, and motility within the eye's vitreous humour, which is normally transparent. It also called Muscae volitantes (from the Latin, meaning "flying flies"), or mouches volantes (from the French).
Floaters are visible because of the shadows they cast on the retin, or their refraction of the light that passes through them, and can appear alone or together with several others in one's field of vision. They may appear as spots, threads, or fragments of cobwebs, which float slowly before the observer's eyes. Since these objects exist within the eye itself, they are not optical illusions but are entoptic phenomena. You should not make your eyes too tired. As for vitamins, yes, they are useful to eyes, especially to your eye problem. Vitamin A is a necessary nutrient for eyes. V-c and V-e can increase eye immunity and good for vision. V-b could boost metabolism. They are all helpful to the floaters. There are also some tips about your meals. Eat more animal liver, eggs, beans, meat, fresh vegetables, fruit, seafood and fish. Eat less spicy food and drink less coffee. Never smoke!