Ocular itch is one of the most characteristic clinical symptoms of allergic conjunctivitis. There are two main mechanisms of action for the production of itch: peripheral and central mechanisms. The peripheral mechanism is the main mechanism of ocular itch, which consists of a variety of itch-causing mediators, such as histamines and non-histamines, that stimulate peripheral nerve endings and eventually travel to the cerebral cortex leading to the onset of itch. The central mechanism is the aggravating factor of itchy eyes, which is mainly caused by some psychogenic activities of the cerebral cortex, such as mental, emotional, attentional and tolerance changes. Central mechanisms are often overlooked by physicians and patients. Patients with itchy eyes most often rub their eyes, and a few patients with severe itchy eyes scratch their conjunctiva with cotton swabs or even sharp objects. These actions can make the patient itch more and more, aggravating the inflammatory response of the eye and possibly even other complications such as corneal damage, keratitis, eyelid skin eczema, etc. Allergic conjunctivitis is one of the most common clinical ocular surface diseases and is mainly caused by contact allergies to various allergens around the patient. The main types of allergens are: plant pollen, willow wool, animal fur debris, airborne dust, dust mites, molds, cosmetics, etc. There are five types of allergic conjunctivitis: seasonal, perennial, spring keratoconjunctivitis, atopic keratoconjunctivitis, and giant papillary keratoconjunctivitis. Ninety percent of the clinical cases are seasonal, perennial allergic conjunctivitis. In the case of seasonal conjunctivitis, the onset is usually seasonal, mainly in the spring. The pathogenesis of allergic conjunctivitis is mainly type I allergic reactions and type IV allergic reactions. In addition, allergic conjunctivitis has a genetic susceptibility, with one parent being atopic, the offspring are 4 times more likely to develop allergies than normal, and both parents being atopic, the offspring are 10 times more likely to develop allergies than normal. What should we do to prevent and treat allergic conjunctivitis? The first and most important thing is to find allergens, avoid their irritation, avoid rubbing the eyes, and improve hygiene and habits. Secondly, you should visit an ophthalmology clinic where your doctor will apply medication (topical, or systemic in severe cases) according to the condition of your eyes. Third, apply cold compresses to the eyes. Fourth, psychological guidance, including parental education, self-psychological suggestion, etc., to interrupt the central mechanism to aggravate the eye itch.