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 may affect one or both eyes and include: 1  Red eyes. 2  Eye pain, discomfort and aching. 3  Blurred vision, cloudy vision.  Light 1  sensitivity. Pupils not reacting to light normally.  Floaters in the 1  eye. Peripheral vision 2  loss. Headache.