The simultaneous experience of dizziness and seeing flashes of light involves both the visual and balance systems. Dizziness can manifest as lightheadedness or a spinning sensation known as vertigo, signaling a disturbance in equilibrium. Flashes of light, medically termed photopsia, are subjective visual perceptions that occur without an external light source, indicating a problem in the visual pathway. Because these two symptoms together can be an early warning sign of a serious underlying condition, they warrant prompt medical evaluation.
Causes Originating in the Eye Structure
Flashes of light that arise directly from the eye are typically a result of physical or mechanical stimulation of the retina. This most commonly occurs when the vitreous gel, the clear, jelly-like substance filling the eyeball, begins to shrink and pull away from the retina, a process known as Posterior Vitreous Detachment (PVD).
PVD is a common, age-related process that affects nearly 75% of people over the age of 65. As the vitreous liquefies, the remaining gel can tug on the retinal surface, causing a brief electrical discharge that is seen as a flash or streak of light, often in the peripheral vision. These flashes are usually short-lived, lasting less than a second, and often diminish in frequency over several weeks as the vitreous completely separates. The accompanying dizziness in these cases may be a secondary reaction to the sudden, disorienting visual disturbance, rather than a direct physical symptom of the eye condition itself.
A more serious condition that follows a similar mechanism is Retinal Detachment. When the vitreous pulls too hard during PVD, it can create a tear in the retina, allowing fluid to pass underneath and separate the retina from its underlying supportive tissue. This detachment is a medical emergency because the separated retinal cells are deprived of oxygen and nutrients, leading to rapid and permanent vision loss if not repaired promptly.
A sudden increase in new floaters, often described as a “shower” of black dots, accompanied by persistent flashes, is a hallmark of a retinal tear or detachment. Patients may also report a shadow or “curtain” effect moving across their field of vision, which represents the area of the detached retina. The flashes are a mechanical signal from the retina being tugged, indicating the need for immediate attention due to the potential for permanent sight loss.
Neurological Events Affecting Vision and Balance
When flashes of light and balance issues originate in the brain, the flashes are caused by abnormal electrical activity rather than mechanical tugging. The most frequent neurological cause is Migraine Aura, which occurs in about 25% of individuals who experience migraines. The visual disturbance, often a scintillating scotoma, begins as a small flickering spot that expands over minutes into a crescent-shaped band of zigzag lines with shimmering edges.
This visual aura is caused by a phenomenon called Cortical Spreading Depression (CSD), a slow-moving wave of electrical over-activity followed by suppression that sweeps across the visual cortex in the back of the brain. The dizziness or vertigo component is often experienced later in the attack or during the postdrome phase, sometimes referred to as a “migraine hangover.”
The postdrome phase, which can last for hours or even days after the headache pain subsides, commonly includes symptoms like exhaustion, difficulty concentrating, and generalized dizziness. The combination of visual aura and subsequent dizziness makes migraine a common cause for the dual symptoms.
A more serious neurological cause is a Transient Ischemic Attack (TIA) or stroke, often involving the vertebral basilar artery system that supplies the back of the brain. Reduced blood flow to the occipital lobe, the brain’s visual processing center, can cause brief, bilateral photopsias, described as broken flashes, due to temporary ischemia. Simultaneously, this impaired blood flow can disrupt the brainstem and cerebellum, which control balance, leading to sudden, severe vertigo, unsteadiness, and difficulty with coordination. These central nervous system events are abrupt in onset and often accompanied by other focal symptoms, serving as a warning sign of impending stroke.
Vestibular and Systemic Balance Disorders
In some cases, the primary symptom is severe vertigo, and the visual disturbances are secondary effects, rather than classic photopsia. The vestibular system, located in the inner ear, is responsible for sensing head position and motion, and disorders here frequently lead to intense dizziness.
Meniere’s Disease, for example, is a chronic condition of the inner ear characterized by episodes of severe vertigo, ringing in the ears (tinnitus), and hearing loss. The profound disequilibrium caused by a Meniere’s episode can overwhelm the brain’s ability to integrate sensory information from the eyes and the inner ear, a condition sometimes called visual vertigo. During these intense spinning sensations, the visual system may struggle to stabilize the world, leading to generalized visual discomfort, flickering, or a sense of movement in the environment. This is distinct from the defined flashes of light seen in retinal or migraine issues.
Labyrinthitis, an inflammation of the inner ear, produces acute, debilitating vertigo that may cause the eyes to move uncontrollably (nystagmus). This results in a sensation of visual blurring or flickering.
Systemic issues that affect the body’s overall circulation can also cause this symptom combination, where the visual disturbance is lightheadedness or dimming of vision. Orthostatic hypotension, a sudden drop in blood pressure upon standing, temporarily reduces blood flow to the brain and eyes. This transient reduction in cerebral perfusion manifests as lightheadedness and a momentary graying or tunnel vision, sometimes perceived as a visual flicker or loss of clarity, due to insufficient oxygen reaching the visual apparatus. Severe dehydration can also lead to temporary low blood pressure and similar visual dimming, making the person feel faint or dizzy.
When to Seek Emergency Medical Care
The combination of flashes of light and dizziness requires immediate professional evaluation, especially if certain “red flag” symptoms are present. Seek emergency medical care immediately if the dizziness is sudden, severe, or accompanied by an inability to walk or maintain balance.
Signs of a serious neurological or ocular event include:
- New or worsening flashes of light coupled with a dark shadow, like a curtain, moving across the vision (potential retinal detachment).
- Slurred speech, weakness, or numbness on one side of the body.
- Sudden double vision.
- A sudden, severe headache described as the “worst headache of your life.”
- Persistent vomiting or a loss of consciousness alongside the dizziness and visual symptoms.
If these severe symptoms occur, call emergency services immediately. Do not attempt to drive yourself or someone else.