One eye is big and the other is small, it may be caused by developmental abnormality or ptosis, which may be congenital or acquired, acquired is mainly seen in myasthenia gravis, motor nerve paralysis, levator muscle injury, etc., which can be treated with medication or surgery under the guidance of a physician. 1. Developmental anomalies: If there is no other discomfort in patients with developmental anomalies, no special treatment can be used; if it affects the aesthetics, surgery can be considered. 2. Congenital ptosis: mainly caused by the nucleus of the motor nerve or hypoplasia of the levator ani muscle, often bilateral, but not necessarily symmetrical, resulting in large and small eyes, can be diagnosed and clarified under the guidance of ophthalmologists, surgical treatment, such as ptosis corrective surgery. 3. Acquired ptosis: Acquired ptosis is mainly caused by myasthenia gravis, actinic nerve palsy, and levator muscle injury, etc. Patients can take oral nutritional nerve medication such as vitamin B, neostigmine and other medications under the guidance of a physician, as well as surgical treatment. It is recommended that patients with double eye size discrepancy should consult a doctor to evaluate their condition and follow the doctor’s instructions for treatment.