Flashing lights in your eyes are perceptions of light that are not actually present in your external environment. People often describe these visual experiences as sudden flashes, streaks of light, or shimmering sparkles. While unsettling, they are a common visual sensation, a manifestation of activity within the eye or visual pathways, rather than external light sources.
Common Explanations
One frequent cause of flashing lights is posterior vitreous detachment (PVD), a natural aging process where the vitreous gel separates from the retina. As the vitreous pulls away, it can tug on the light-sensitive retina, causing brief, lightning-like flashes or camera-flash perceptions, particularly in peripheral vision. This process is generally harmless, though it can sometimes precede more serious conditions.
Another common explanation involves ocular migraines, also known as migraine auras, which are visual disturbances that can occur with or without a headache. These typically manifest as shimmering, jagged lines, often resembling a C-shape, or as a spreading blind spot that gradually expands across the visual field. The visual phenomena associated with migraines usually resolve within 20 to 30 minutes.
Applying pressure to the eyes, such as from rubbing them vigorously, can temporarily induce phosphenes, which are perceived flashes of light. This occurs because mechanical stimulation of the retina can trigger the light-sensing cells to send signals to the brain, even in the absence of actual light. Eye strain or fatigue from prolonged visual tasks may also occasionally lead to minor, fleeting visual disturbances.
Urgent Medical Concerns
The most serious cause of flashing lights in the eyes is a retinal detachment, a condition where the retina separates from the underlying tissue that supplies it with oxygen and nutrients. Flashes associated with a retinal detachment are typically sudden in onset, more numerous, and often described as brighter or more intense than those from PVD. These flashes frequently occur alongside a sudden increase in new floaters, which appear as dark spots, “cobwebs,” or “specks” drifting across the vision.
Retinal tears, which can precede a full detachment, also cause similar sudden flashes and new floaters as the vitreous pulls on and tears the retina. If left untreated, a retinal tear can allow fluid to pass beneath the retina, leading to a detachment. A curtain-like shadow or a dark area that moves across the field of vision is a strong indicator of a developing or existing retinal detachment, representing a medical emergency that requires immediate attention.
Bleeding into the vitreous gel, known as a vitreous hemorrhage, can also cause flashes of light or a sudden reduction in vision. This bleeding often results from conditions like diabetic retinopathy or a retinal tear, where fragile blood vessels leak into the gel. While less common, certain inflammatory conditions affecting the optic nerve, such as optic neuritis, or acute angle-closure glaucoma, a sudden rise in eye pressure, can also sometimes be associated with perceived flashes or visual disturbances.
When to Seek Medical Attention
Seeking immediate medical attention is advisable if you experience a sudden onset of new flashing lights, especially if they are accompanied by a sudden increase in the number of floaters. Any perception of a shadow or a “curtain” moving across your field of vision, or a sudden, unexplained decrease in your overall vision, warrants an emergency visit to an ophthalmologist or an emergency room. These symptoms are concerning for a retinal tear or detachment, which require prompt intervention to preserve vision.
You should seek prompt attention from an eye doctor if you experience persistent flashing lights that do not resolve on their own, even if they are not accompanied by other alarming symptoms. This is particularly important if the flashes are associated with other concerning symptoms such as eye pain, redness, or a persistent headache. Scheduling an appointment with an eye care professional soon can help determine the underlying cause and ensure appropriate management.
Even if flashing lights are benign and attributed to common causes like posterior vitreous detachment, it is still recommended to discuss them with an eye doctor during your next routine eye examination. This allows a professional to document the symptom and ensure there are no subtle signs of more serious underlying conditions. Regular eye check-ups are important for monitoring eye health and detecting potential issues early.
Diagnosis and Management
When you visit an eye doctor for flashing lights, a comprehensive dilated eye examination is typically performed. This involves administering eye drops to widen your pupils, allowing the ophthalmologist to thoroughly examine the retina, optic nerve, and vitreous gel in the back of the eye. An ophthalmoscope is used to view these structures in detail, often revealing the cause of the flashes.
Additional diagnostic imaging may be used for a more detailed view of the eye’s internal structures. Optical coherence tomography (OCT) provides cross-sectional images of the retina, while an ultrasound may be performed if the view to the retina is obscured, such as by a dense vitreous hemorrhage. These techniques confirm diagnosis and determine the extent of any damage.
Management varies significantly depending on the underlying cause. For benign conditions like posterior vitreous detachment, no specific treatment is usually required, but regular monitoring may be recommended to ensure no complications arise. If a retinal tear is identified, laser photocoagulation or cryopexy (freezing) can seal the tear and prevent it from progressing to a full retinal detachment. In cases of retinal detachment, surgical procedures such as vitrectomy or scleral buckling are necessary to reattach the retina and restore vision. Following the doctor’s recommendations for follow-up appointments monitors recovery and ensures long-term eye health.