Flashes and Floaters

Most people experience flashes of light and floaters or specks in the field of vision from time to time.  Flashes and floaters occur naturally with increasing age.  Flashes and floaters that occur suddenly or are accompanied by vision loss may be a sign of a serious problem.  You should contact your doctor immediately if you experience an abrupt onset of flashes, floaters, or vision changes.

The vision process occurs as light rays enter the front of your eye and are interpreted by your brain as images.  Light rays first enter your eye through the cornea, a clear dome that helps your eyes focus.

The anterior chamber is located behind the cornea and in front of the iris.  The anterior chamber is filled with a fluid that maintains eye pressure, nourishes the eye, and keeps it healthy.  The fluid is constantly produced and drained from the anterior chamber into the bloodstream. 

The iris is the colored part of your eye.  The iris contains two sets of muscles.  The muscles work to make the pupil of your eye larger or smaller.  The pupil is the black circle in the center of your iris.  It changes size to allow more or less light to enter your eye.

After light comes through the pupil, it enters the lens.  The lens is a clear curved disc.  Muscles adjust the curve in the lens to focus clear images on the retina.  The retina is located at the back of your eye.

Your inner eye, or the space between the posterior chamber behind the lens and the retina, is the vitreous body.  It is filled with a clear gel substance that gives the eye its shape.  Light rays pass through the gel on their way from the lens to the retina.

The retina is a thin tissue layer that contains millions of nerve cells.  The nerve cells are sensitive to light.  Cones and rods are specialized receptor cells.  Cones are specialized for color vision and detailed vision, such as for reading or identifying distant objects.  Rods perceive blacks, whites, and grays, but not colors.  They detect general shapes.  Rods are used for night vision and peripheral vision.  High concentrations of rods at the outer portions of your retina act as motion detectors in your peripheral or side vision. 

The greatest concentration of cones is found in the macula and fovea at the center of the retina.  The macula is the center of visual attention.  The fovea is the site of visual acuity or best visual sharpness.

The receptor cells in the retina send nerve messages about what you see to the optic nerve.  The optic nerves extend from the back of each eye and join together in the brain at the optic chiasm.  From the optic chiasm, the nerve signals travel along two optic tracts in the brain and eventually to the occipital cortex.

Flashes of light and floaters or specks in the field of vision occur in healthy people, but may also be a sign of serious problems.  The gel that fills the eye is very similar to Jell-O.  After an injury, or with aging the gel begins to convert back to water and powder.  This would be similar to the reverse process of making Jell-O. Jell-O is sticky and as it changes it peels away from the surface of the retina pulling on the retina.  This causes you to see flashes of light. Instead of feeling things in your eye, you see them.  The floaters in most cases is the powder separating out of the gel. A s you grow older, it is common to experience flashes.  However, if flashes occur suddenly, it may also be a sign that the retina is torn and the floaters could be blood in the eye.  In this case, you should contact your doctor immediately as it is not possible to tell if the flashes are simply from normal aging, or a tear, without a thorough eye exam.

If floaters occur suddenly and you lose peripheral (side) vision, it may be a sign that the retina is torn or detached.  Bleeding in the vitreous can also occur from advanced diabetic retinopathy or other retina conditions.  You should contact your doctor immediately if you experience such sudden symptoms.

Flashes may appear as flashes of light or light that appears in a lightening streak pattern.  Floaters appear as spots or specs in your field of vision.  Flashes and floaters may occur naturally as you grow older.  Floaters eventually settle at the bottom of your eye and become less noticeable.  However, sudden symptoms or vision changes can be the sign of a serious condition.  You should contact your doctor immediately if you experience a sudden onset of flashes and floaters, decreased peripheral vision, or changed vision.

Your doctor will review your medical history and perform a thorough eye examination.  Tonometry may be used to measure the pressure inside of your eye.  A visual acuity test may be used to determine how well you see at different distances.   

In some cases, a fluorescein angiogram is used to detect blood circulation problems in the structures that are located in the back of your eyes.  The test uses an injected dye and a special camera to take photos of blood vessels. 

Flashes and floaters that are part of the normal aging process do not require treatment.  Your retinas should be checked as part of your regular comprehensive eye examination.  If you are diagnosed with a retinal tear or detachment, diabetic retinopathy, or another retina disorder, your doctor will discuss the appropriate treatment options for the particular condition with you.  Depending on the condition that you have, treatment options may include laser surgery or vitrectomy, removing some of the gel of the eye.