Itching inside the eyes may be caused by allergic conjunctivitis, blepharitis, keratitis and other diseases. 1. Allergic conjunctivitis: Allergic conjunctivitis is mainly caused by allergen exposure, and patients will experience symptoms such as itchy eyes, burning sensation in the eyes, and increased secretions. Allergic conjunctivitis also leads to symptoms such as eyelid swelling, tearing, and loss of vision. 2. Blepharitis: The cause of blepharitis is more complex, considering psoriasis, atopic dermatitis and other diseases. The main symptoms of patients are burning, itching and stinging in the eyes, as well as increased secretion, swelling and erosion. 3. Keratitis: Keratitis is mainly due to the infection of pathogens such as celine, virus, etc. The main symptoms of patients are eye pain, photophobia, tearing and other symptoms. In addition, patients with keratitis will also have symptoms of eye irritation, which will lead to the phenomenon of itching inside the eyes. Patients with symptoms of itchy eyes should seek medical attention, identify the cause of the disease, and follow the doctor’s instructions for treatment.