Eye floaters are spots in your vision. They may look to you like black or gray specks, strings or cobwebs that drift about when you move your eyes and appear to dart away when you try to look at them directly.
Most eye floaters are caused by age-related changes that occur as the jelly-like substance (vitreous) inside your eyes becomes more liquid. Microscopic fibers within the vitreous tend to clump and can cast tiny shadows on your retina, which appear to you as floaters.
If you notice a sudden increase in eye floaters, contact an eye specialist immediately — especially if you also see light flashes or lose your peripheral vision. These can be symptoms of an emergency that requires prompt attention.