Q: I have been noticing little black specks or cobwebs in my vision off and on for a long time. But last week I was startled to see actual flashes of light in my side vision. People tell me this is normal, but I am not so sure. How do we know?
A: Your symptoms are pretty common….mostly. Many people at some stage in life will notice “floaters” in their vision at times. These are more of a nuisance or distraction, but certainly are important. Generally, the cause is a natural change in the “vitreous” gel that fills our eyes. While very firm ( like Jell-O ) in our youth, the gel becomes more watery over time. This aging change allows the tiny fibers that gave it “firmness” to begin clumping together and floating in the now watery vitreous. What you see is actually the shadows of those fibers! Of course they can take any number of shapes and arrangements…..cobwebs, clumps, strands, etc. If only this is occurring the benign nature of such requires no medical intervention.
However, seeing flashes is different. When our retina, that thin nerve layer that lines our eyes ( like plastic wrap in your kitchen ) has damage or separation, it sends impulses to our brain that we see as flashes. Sometimes this pulling can detach the nerve layer from its base of nutrition and blood supply. This is called a “retinal detachment” and is very urgent to treat. If the nerve layer is separated for too long, it cannot regain function….meaning you lose part of your vision forever. These urgent disorders can be actual tearing or ripping of the nerve layer, or just separation. While treatments are different, time is of the essence. Immediate diagnosis and treatment is critical.
Lastly, and least common, flashes can be caused by brain tumors. A mass inside our brain can press on our optic nerve and give symptoms like this. Suspicion of such may require MRI or CT scanning to locate any intracranial tumor or mass.
As you would assume, seeing your eye doctor right away is essential. Treatments can be very effective in preventing or restoring sight loss, but time is critical. Lastly, I should add, all three of these potential problems can present without any pain or discomfort at all. Vision symptoms may be the only clues.