Floaters look like small, dark spots or strands that float in front of your eyes. Floaters are very common and normally harmless. They are more common if you are short sighted or as you get older.
Some people notice flashes of light. These can be due to the movement of the gel inside the eye.
Very occasionally, flashes or an increase in floaters can be a sign of retinal detachment, which needs treating as soon as possible. This is more common as you get older, or in people who are short sighted or have had eye surgery.