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.
Blurry vision, ghost images and nighttime halos around lights all can be warning signs of eye problems. 1  A flood of spots and floaters in your field of vision. 2  A sensation that a dark curtain has settled across your field of view. 3  Sudden eye pain, redness, nausea and vomiting.  Double vision, double images or ghost images.