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.
When symptoms are present, they can include: 1  Vision that is cloudy, blurry, foggy or filmy. 2  Sudden short sightedness. 3  Changes in the way you see colour, especially yellow.  Problems driving at night because oncoming headlights are 1  distracting. Problems with glare.  Double 1  vision. Sudden temporary improvement in close-up vision.