a. Very long differential diagnosis, including medications (e.g., anticholinergics or antihistamines), autoimmune diseases (e.g., Sjögren), CN V or VII lesions b. The eye may appear normal, or may be mildly injected c. Patients may complain of a foreign body sensation d. Treat with artificial tears during the day. Consider a lubricating ointment at night. Many other treatments are available