There are four types of hypersensitivity reaction, classified according to the way in which the ALLERGEN or ANTIGEN activates the reaction. The classic allergic reaction is the type I hypersensitivity reaction, with exposure to an external substance (the allergen) initiating the IMMUNE RESPONSE.
Flickering lights in vision, Headache and Sudden flash of lights. WebMD Symptom Checker helps you find the most common medical conditions indicated by the symptoms flickering lights in vision, headache and sudden flash of lights including Migraine headache (adult), Tension headache, and Ocular migraine.
Regular migraines can also cause vision problems, called an aura, which can involve flashing lights and blind spots in your vision. But these symptoms usually appear in both eyes. See your doctor to find out if you have ocular migraines. He can rule out other conditions that can cause similar symptoms.