WebMD states that eye floaters generally do not go away once they form, but do become less noticeable over time. If the floater is seriously affecting someone's vision, he or she should consult an optometrist.
Most floaters are harmless. They are tiny bits of coagulated collagen that accrue in the liquid at the back of the eye, known as the vitreous humour. The number of floaters a person has increases with age. If an abnormal number of floaters appear in a short amount of time or are accompanied by eye pain, this could be symptomatic of severe eye injury requiring immediate medical attention.