Floaters can be caused by many things:
- As we age, the vitreous gel in the eye may thicken and shrink, causing little clumps to form.
- If the vitreous gel pulls away from its attachments to the retina, called a posterior vitreous detachment (PVD), it can clump up and make a larger floater
- Sometimes tears in the retina can occur, releasing cells into the middle of the eye that appear as many small floaters.
- Flashes (photopsia) also may occur after a blow to the head, often called “seeing stars.”
- Inflammation in the eye can cause floaters to appear in the vision.
Some people experience flashes of light that appear as jagged lines or “heat waves” in both eyes, often lasting 10-20 minutes. These types of flashes are usually caused by a spasm of blood vessels in the brain, which is called a migraine.