Flashing Lights in Vision: Causes, Symptoms, and When to Seek Care

This is the most common cause of flashing lights, especially in people over 50. As the vitreous gel shrinks with age, it gradually pulls away from the retina in a process called posterior vitreous detachment, or PVD. Research shows that about 24 percent of adults aged 50 to 59 and nearly 87 percent of people over 80 will develop PVD. Most cases are harmless and require only monitoring, but in some situations this pulling action can tear the retina, which is why any new flashes should be evaluated.

When the vitreous pulls too forcefully on the retina, it can create a tear or hole. If fluid seeps through this opening, it can cause the retina to lift away from the underlying tissue, a condition called retinal detachment. Without prompt treatment, retinal detachment can lead to permanent vision loss. Warning signs include flashes combined with a sudden shower of new floaters, a dark curtain or shadow in your vision, or loss of peripheral vision.

Getting hit in the eye, experiencing head trauma, or even rubbing your eyes very hard can cause temporary flashes. The mechanical pressure or impact can stimulate the retinal cells or cause the vitreous to move suddenly. While these flashes may seem harmless, any trauma-related visual symptoms should be evaluated to rule out hidden damage to the eye structures.

Migraines can begin with visual disturbances called auras, which may include sparkling lights, zigzag lines, shimmering patterns, or bright spots that move across your vision. About one in four people with migraines experience visual auras, which usually affect both eyes and last anywhere from 5 to 60 minutes. A headache may follow the aura, though some people experience the visual symptoms without developing a headache. Migraine-related flashes look different from retinal flashes and are typically more geometric or patterned in appearance.

Less common causes of flashing lights include retinal diseases such as retinitis pigmentosa, abnormal blood vessel growth under the retina, inflammatory conditions affecting the eye, and hereditary retinal disorders that affect how the retina processes light. Our ophthalmologists at ReFocus Eye Health Penndel can perform comprehensive testing to identify these conditions.

In some cases, flashing lights can be related to problems affecting the visual pathways in the brain rather than the eye itself. These can include seizures, transient ischemic attacks, strokes, or rarely, tumors affecting the visual cortex. If a thorough eye examination does not reveal an eye-related cause for your flashes, your doctor may recommend neurological evaluation.

Certain medications, particularly those affecting the nervous system, can sometimes cause visual disturbances including flashing lights. If you start a new medication and then develop flashes, let your eye doctor know. Always bring a complete list of your medications to your appointment so our team can consider any possible connections.

Your appointment will begin with detailed questions about your flashes. Our ophthalmologists will ask when they started, how often they occur, what they look like, whether they affect one or both eyes, and if you have any other symptoms. Be prepared to discuss your medical history, medications, any recent injuries, and your family eye health history.

You will read letters on a chart to measure the sharpness of your vision. This establishes a baseline and helps identify any changes in your ability to see clearly. We test each eye separately to compare function and detect any differences between the two eyes.

A gentle test measures the pressure inside your eyes. This is important for screening for glaucoma and ruling out other conditions that can cause visual symptoms. Elevated eye pressure combined with certain symptoms may indicate an acute problem requiring immediate treatment.

This is the most important part of your examination for flashes. Special eye drops are placed in your eyes to widen your pupils, allowing our ophthalmologists to see the entire back of your eye, including your retina, optic nerve, and blood vessels. We carefully examine every part of your retina, paying special attention to the peripheral areas where tears are most likely to occur. Your vision will be blurry and you will be sensitive to light for several hours after dilation, so plan to have someone drive you home.

Using special lenses and bright lights, your doctor will perform a thorough inspection of your retina while your eyes are dilated. This allows us to see all the way to the edges of your retina, where problems often begin. If needed, we may gently press on the outside of your eye with a small instrument to view the far peripheral retina more clearly.

In some cases, additional testing provides more detailed information. Optical coherence tomography, or OCT, creates cross-sectional images of your retina to examine its layers in detail. Ultrasound imaging may be used if the view of your retina is blocked by bleeding or cloudiness inside the eye. These painless tests help our team at ReFocus Eye Health Penndel make accurate diagnoses and treatment decisions.

No, flashes are not always serious. Many people experience occasional flashes as they age without any underlying disease, particularly as the vitreous naturally separates from the retina. However, because new, frequent, or changing flashes can be a warning sign of a retinal tear or detachment, they should always be evaluated with a dilated eye examination to ensure your retina is healthy.

Migraine-related flashes often appear as zigzag lines, shimmering or sparkling lights, or geometric patterns. They typically affect both eyes equally, last between 5 and 60 minutes, and may be followed by a headache. Eye-related flashes are usually very brief sparks or streaks lasting less than a second, often appear in just one eye, occur in your peripheral vision, and can be associated with new floaters. However, the only way to know for certain is to have a dilated eye examination.

You cannot prevent the age-related changes to the vitreous that cause most flashes. However, you can reduce your risk of complications by protecting your eyes from injury, controlling health conditions such as diabetes and high blood pressure, avoiding smoking, maintaining a healthy diet, and having regular comprehensive eye examinations. These steps help keep your eyes as healthy as possible and allow early detection of any problems.

Yes, flashes can occur in one or both eyes. When both eyes are affected simultaneously, especially if the flashes look like patterns, auras, or organized shapes, migraine or neurological causes are more likely than problems with the retina. Retinal problems usually affect only one eye at a time, since the changes in the vitreous happen independently in each eye.

You should not wait to seek evaluation for new flashes. If you notice flashing lights for the first time, especially if they are accompanied by new floaters, a shadow in your vision, or any vision loss, contact an eye doctor immediately. Even if you have no other symptoms, new flashes warrant a prompt dilated eye examination to rule out retinal tears. Early detection and treatment of retinal problems significantly improves outcomes.

Flashes are much less common in children because the age-related vitreous changes that cause most flashes do not occur in young people. However, children can experience flashes related to migraines, eye injuries, or rarely, inherited retinal conditions. Any child who complains of seeing flashing lights should be evaluated by an eye doctor to determine the cause and ensure appropriate treatment.

Flashes are often more noticeable in the dark or in dim lighting because there are fewer competing visual stimuli. If they are occasional, have been stable for a long time, and you have had a recent normal eye examination, they are likely harmless. However, if they are new, becoming more frequent, or are associated with any other symptoms, they should be evaluated regardless of when they occur.

Many harmless flashes from uncomplicated posterior vitreous detachment will lessen or stop completely over weeks to months as the vitreous settles into its new position and your brain learns to ignore the stimulation. However, flashes caused by ongoing retinal problems will not resolve without treatment. Only a dilated eye examination can determine whether your flashes are likely to improve on their own or require intervention.

The flashes themselves do not directly damage your vision. However, if they are a symptom of an underlying condition such as a retinal tear or detachment, permanent vision loss can occur if the condition is not treated promptly. This is why immediate evaluation is so important when you experience new or changing flashes.

Not always. If a retinal tear is discovered before the retina detaches, it can often be treated with an in-office laser or freezing procedure, avoiding the need for surgery. If a detachment has occurred, surgery is necessary, but the urgency and type of surgery depend on the location and extent of the detachment. Detachments affecting the central vision require more urgent treatment than those affecting only the peripheral retina. Prompt evaluation increases the chance of successful treatment with less invasive procedures.

Yes, some medications can cause visual disturbances including flashes of light, though this is not common. Medications that affect the nervous system, certain antibiotics, and some other drugs have been reported to cause photopsia. Always provide a complete list of your medications, including over-the-counter drugs and supplements, to your eye doctor if you experience new visual symptoms.

If you are experiencing flashes for the first time or if there is any change in the pattern or frequency of your flashes, yes, a dilated eye examination is essential. Dilation allows your doctor to examine the entire retina, including the far peripheral areas where tears most commonly occur, to check for any signs of damage. If you have chronic stable flashes that have been thoroughly evaluated in the past, your doctor will advise you on when repeat dilated examinations are needed.

If your flashes are from uncomplicated posterior vitreous detachment and your retina is healthy, you can usually continue normal activities. However, until you have been evaluated, it is wise to avoid activities that could worsen a potential retinal problem, such as contact sports, heavy lifting, activities involving sudden jarring motions, or inversions like yoga headstands. After your examination, your doctor will provide specific guidance based on your diagnosis.