The main causes of itchy eyes include eye allergy, eye infection, foreign body irritation or visual fatigue. 1. Eye allergy: patients with allergies can have eye allergic reactions when they come into contact with allergens, which may cause itchy eyes, conjunctival congestion and other uncomfortable symptoms. 2. Eye infections: viruses, bacteria, chlamydia and other germs infect the eye tissue, under the stimulation of inflammation, patients may experience eye itching, photophobia, tearing and other uncomfortable symptoms. 3. Foreign body irritation: If patients wear contact lenses for a long time or dust and sand enter into the eyes, it will also lead to the symptoms of itchy eyes. 4. Visual fatigue: If the patient looks at the cell phone or computer for a long time and lack of sleep can lead to visual fatigue, the patient may appear dry eyes, itchy, soreness and other uncomfortable symptoms. It is recommended that patients with obvious itchy eyes should consult a doctor in time to assess their condition and follow the doctor’s instructions for treatment.