Flashes and Floaters: When Are They Normal—and When Are They an Emergency?

Keshav Narain, M.D.
3 hours ago
3 min read

Have you ever noticed tiny specks drifting across your vision, or brief flashes of light that appear out of nowhere—almost like camera flashes at the corner of your eye? For many people, these moments are unsettling. A common question patients ask is whether flashes and floaters are simply a normal part of aging or a warning sign of something more serious happening inside the eye. The answer, as with many things in medicine, depends on the details.

South Bay Retina | Identifying Flashes and Floaters: Understand when these common eye phenomena are normal and when you should seek medical attention to protect your vision. — Identifying Flashes and Floaters: Understand when these common eye phenomena are normal and when you should seek medical attention to protect your vision.

Flashes and floaters are among the most frequent reasons people seek urgent eye care, and for good reason. While they are often harmless, they can sometimes signal conditions that require immediate attention to protect your vision.

Floaters are small shapes that appear to drift across your field of vision. They may look like dots, strings, cobwebs, or shadows that move when you move your eyes and seem to dart away when you try to focus on them. These are usually caused by tiny clumps within the vitreous, the clear, gel-like substance that fills the inside of the eye. As we age, the vitreous naturally becomes more liquid and can shrink slightly, causing these microscopic fibers to cast shadows on the retina. In many cases, floaters are a normal age-related change and become less noticeable over time as the brain adapts.

Flashes, on the other hand, are brief streaks or sparks of light that often appear in peripheral vision. They occur when the vitreous tugs on the retina, stimulating the light-sensing cells even though no actual light is entering the eye. This process is commonly associated with a posterior vitreous detachment, a condition where the vitreous separates from the retina as part of normal aging. While this sounds alarming, it is extremely common, especially after age 50, and often resolves without permanent problems.

However, the key issue is not just the presence of flashes or floaters, but how they appear and change. A sudden onset of many new floaters, especially if accompanied by persistent flashes of light, can be a warning sign of a retinal tear or retinal detachment. The retina is the delicate layer of tissue at the back of the eye responsible for vision, and if it tears or detaches, vision can be permanently affected if not treated promptly. Patients sometimes describe this as a sudden “shower” of floaters, a dark curtain or shadow creeping across their vision, or a noticeable loss of side vision.

Certain risk factors make these symptoms more concerning. People who are highly nearsighted, have had previous eye surgery such as cataract surgery, experienced eye trauma, or have a family history of retinal problems are at higher risk for retinal tears and detachments. In these individuals, flashes and floaters should never be ignored.

The most important takeaway is this: flashes and floaters are common, but sudden changes are not something to watch and wait on. Any abrupt increase in floaters, new flashes of light, or the appearance of a shadow or curtain in your vision should be treated as an eye emergency. A comprehensive dilated eye exam allows an ophthalmologist to examine the retina carefully and determine whether the symptoms are benign or require urgent treatment.

If your floaters have been stable for years and your eye exam is normal, reassurance and observation are often all that’s needed. Staying aware of your vision and recognizing changes early is one of the most powerful tools you have to protect your eyesight. When it comes to retinal health, timely evaluation can make the difference between preserving vision and permanent vision loss.

If you or someone you care about is experiencing flashes or floaters and feels unsure about what they mean, it’s always better to err on the side of caution. Early evaluation not only provides peace of mind, but can be vision-saving when intervention is needed.