Colds do not cause itchy eyes. The condition is considered to be an acute attack of a chronic underlying disease due to a cold, such as with chronic allergic conjunctivitis, chronic allergic rhinitis, etc. When the body’s resistance decreases and is invaded by pathogens that cause an inflammatory response in the mucous membrane of the upper respiratory tract, this induces an acute attack of chronic respiratory disease, with marked congestion, edema or even exudation of inflammatory substances from the conjunctiva and intense itching. Clinically, blood tests can show a significant increase in eosinophils to clarify the diagnosis, and if necessary, allergens can be detected and timely anti-allergy treatment can relieve the symptoms.