There are many reasons why a person’s left eye rolls up when eating or talking, and the most common reasons include an inverted eyelash or strabismus in the left eye. In patients with upturned left eyes, the left eyeball is turned upward, with most of the white of the eye exposed, while the right eyeball is in the center. If the eyelashes on the patient’s left eyelid curl inward and irritate the patient’s ocular surface tissues such as the conjunctiva and cornea, due to the sensitivity of the corneal nerves, the patient’s left eye may involuntarily roll upward during eating and talking to avoid the irritation of the eyelashes on the ocular tissues. Left eye upturning may also be related to strabismus, usually vertical strabismus, which can be manifested as the right black eyeball is in the center while the left black eyeball is upturned when eating and talking and looking ahead, which may be caused by damage or lesion of the upper rectus muscle of the eye. It is recommended that patients with upturned eyes and other discomforts should seek prompt medical attention to evaluate their condition and follow the doctor’s instructions for treatment.