Although most flashes and floaters occur in people with healthy or merely nearsighted eyes, they can be symptoms of a serious problem including injury and retinal or posterior vitreous detachments. Flashes in vision are caused by pressure on the retina—the bundle of nerves in the back of the eye where images are detected and transmitted to the brain, causing patients to experience flashing lights or lightning streaks in their vision.
What Causes Floaters?
Conditions that can cause floaters to appear in or fill up the field of vision include:
- Older age
- Migraines and headaches
- Nearsightedness (myopia)
- Inflammation of the eye
- A history of eye surgery (such as having had cataract surgery)
- Retinal problems, including detachment or bleeding
- Diabetes
- Eye injury or trauma




