They are usually invisible in dim light. Floaters almost never go away, but with time they may shrink and people tend to adjust to their presence. The retina does not contain the special nerve fibers that are required to feel pain. Thus, when the vitreous pulls on the retina, it is completely painless. However, when the vitreous pulls on the retina, it triggers the rods and cones.
Flashes of light indicate that the vitreous is actively pulling on the retina.
While floaters never go away, light flashes will diminish as the vitreous pulling subsides. This usually occurs over a period of 4 to 6 weeks. These light flashes are like small, brief lightning bolts, and are usually seen in the side vision. These flashes are so weak, that are seen only in very dim light. Occasionally, migraines, with or without headaches, are associated with flashing lights.