Migraine with Aura: This condition is characterized by visual disturbances, including flashing lights in the periphery of the vision, which can be a precursor to a migraine headache. The symptoms often start in the center of the visual field and move outward, which aligns with the description of eyes flashing periphery.

Ocular Migraine: Similar to migraine with aura, but the visual symptoms may occur without a subsequent headache. The flashing lights can be confined to one eye and may be accompanied by other visual disturbances.
Dry Eye Syndrome: While less commonly associated with flashing lights, severe dry eye can cause a variety of visual disturbances, including flashes of light, due to irritation of the cornea.
Posterior Vitreous Detachment (PVD): A condition where the vitreous gel separates from the retina, causing flashes of light, especially in the periphery. It's a common condition, often related to aging.

Retinal Detachment: A medical emergency where the retina separates from the back of the eye. Symptoms include sudden flashes of light, especially in the periphery, and must be treated promptly to preserve vision.
Stroke or Transient Ischemic Attack (TIA): Visual disturbances, including flashing lights, can be a symptom of a stroke or TIA, especially if the symptoms are transient and accompanied by other neurological deficits.

Occipital Lobe Seizures: Rare seizures that can cause visual hallucinations, including flashing lights, due to abnormal electrical activity in the part of the brain that processes visual information.
Vitreous Hemorrhage: Bleeding into the vitreous gel can cause sudden visual disturbances, including flashes of light, and is a medical emergency requiring immediate attention.