The patient’s eyes become smaller, which may be caused by eye infection, eye trauma, eye allergy, ptosis, eyelid skin laxity, eyeball inversion and so on. Due to eye inflammation caused by the patient’s eyelids red and swollen, from the outside, the patient can have the feeling of eyes become smaller, such as conjunctivitis, keratitis, blepharitis, etc., mainly caused by the patient’s eyes localized by bacteria, viruses and other pathogenic microorganisms infection. If the patient’s eyes are traumatized, resulting in bruising and swelling of the eyelids, the patient may experience difficulty in opening the eyes, and therefore the patient’s eyes may appear to be smaller. If the patient is exposed to allergens, such as pollen, hair, etc., an allergic reaction can occur in the eyes, resulting in swelling of the eyelids, so the patient’s eyes look smaller. Ptosis due to heredity, trauma, myasthenia gravis, motor nerve palsy, or loose eyelid skin due to old age can also cause the patient’s eyes to look smaller. In addition, atrophy of the eyeball, reduction of intraorbital fat, fracture of the orbital wall and other causes lead to the patient’s eyeball sinking, which can also make the patient’s eyes look smaller. It is recommended that patients with small eyes seek medical attention to evaluate their condition and follow their doctor’s instructions.