Flashes and Floaters:
Information for adults

Flashes and floaters describes a condition that comes from changes in the back chamber of the eye (the posterior chamber, also known as the vitreous cavity). The posterior chamber is filled with a material called vitreous (the vitreous body) which, at birth, is jelly-like in consistency. With normal aging, the vitreous begins to break down into a mixture of clear liquid and pieces of debris, which appear as specks of dust, lint, lines, branching twigs, or spiders. Ultimately, the vitreous becomes so loose that it often detaches from its normal attachments to the retina. When this occurs, it is called a posterior vitreous detachment (PVD). After the posterior vitreous detachment has occurred, one will often see a fairly large, ring-like floater. About 15% of people with a posterior vitreous detachment also have an associated retinal tear, which requires medical attention.

There are 3 rather uncommon conditions that can cause floaters, which are:

• Asteroid hyalosis – a benign condition where there are spherical white bodies in the vitreous; it is thought to be related to diabetes and high cholesterol levels.
• Synchysis scintillans – a degenerative condition with cholesterol crystals in the vitreous, usually due to previous eye injury or internal eye inflammatory disease.
• Amyloid degeneration – a very rare degenerative condition with amyloid deposits in the vitreous and elsewhere in the body.

The flashes of light we see in this normal aging process can be either in the form of lightening bolts, shooting stars, sparks, or an arc of light to the side. The latter is most often what occurs when the vitreous has become so loose that it sloshes around and, when it strikes the retina (the electric membrane of the eye), it sets off an arc of light to the side of vision. Normally, it is either the vitreous tugging on the retina or bouncing against it that causes the sparks and shooting stars phenomenon. But flashes and floaters may have more serious causes and consequences if the floaters are from blood, inflammatory or infectious processes within the eye, torn retinal tissue, or associated with a retinal detachment. Flashes may also occur with migraine headaches.