What Causes Flashes?

Flashes are caused by the vitreous gel tugging on the retina. If the gel actually separates from the retina (Posterior Vitreous Detachment), flashes of light may appear periodically for several weeks. As with floaters, flashes are usually a result of the aging process and do not indicate a serious vision problem. However, flashes which appear along with a large number of new floaters or with a loss of part of the field of vision may indicate retinal detachment, requiring an immediate eye exam.