Floaters. It sounds as if you have had a posterior vitreous detachment. This is a situation where the vitreous(jelly) of the eye detaches (not a retinal detachment), it then "crumples" up leaving dots, spots, strands of blurry vitreous; i.e. The "floater". You should have an exam to ensure the incident did not tear the retina, which could lead to a retinal detachment.
You don't. Floaters are pieces of the vitreous gel inside the eye that cast shadows on the retina. They usually harmless, but annoying. You'll eventually learn to tune it out or it will settle out of your central vision. Aside from an eye surgery that no retinal surgeon would likely perform due to the risks, there is no way to get rid of it. Patience will take care of it.