Flashes and Floaters

The space between the crystalline lens and the retina is filled with a clear, gel-like substance called vitreous. As we get older, the vitreous thins and may separate from the back of the eye. This is called a posterior vitreous detachment (PVD). When the vitreous pulls free from the retina, light flashes or floaters often accompany it.

PVD is the most common cause of floaters and light flashes. It is usually harmless and no treatment is necessary. However, floaters may also be caused by retinal tears, retinal detachment, infection, inflammation, or hemorrhage.

If the vision is significantly affected a vitrectomy (surgical removal of the vitreous) may be considered. This treatment is rarely needed since floaters typically become less bothersome over a period of weeks to months.

Typically light flashes are a result of the vitreous gel pulling on the retina. This may occur with PVD, an injury, or a blow to the eye. (Have you ever seen stars after bumping your head?) Occasionally, flashes of light are caused by neurologic problems such as a migraine headache. In this case, the flashes of light are seen in both eyes and usually last several minutes.

When should you see your doctor?
If you notice a sudden shower of floaters, new light flashes, a veil or curtain obstructing your vision, or decrease in your vision, notify your physician immediately. Your doctor will dilate the pupil with drops and examine inside the eye.

You can monitor your symptoms by covering one eye at a time and testing your vision. While looking straight ahead, note any obstructions or change in the quality of your central and peripheral vision. Note the duration and intensity of your symptoms, comparing the vision of both eyes. Notify your doctor if you detect any significant changes.