Facial palsy is usually caused by inflammation or irritation of the cornea or conjunctiva. Facial palsy generally refers to peripheral facial nerve palsy, where peripheral damage to the facial nerve causes muscle paralysis on one side, resulting in incomplete eyelid closure on the paralyzed side, crooked corners of the mouth, and shallow or absent frontal lines. This results in a chronic inability to blink or close the eyes, and even when sleeping, the eyelids remain open, leaving the cornea exposed to the air for long periods of time, unprotected by the eyelids and lacking in tear fluid. Dryness for long periods of time can lead to tearing, and if dry keratitis or exposure keratitis occurs, the inflammation can lead to increased tearing and even serious infection with the possibility of blindness.