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.
Symptoms can include. 1  Blurry or double vision. 2  Rings, flashing lights, or blank spots. 3  Dark or floating spots. 4  Pain or pressure in one or both of your eyes. 5  Trouble seeing things out of the corners of your eyes.