This course reviews the neurosensory pathways of dry eye and the pathophysiological overlap with neuropathic pain and photophobia.  Emphasis will be placed on differentiating primary dry eye disease from secondary dry eye disease and neuropathic pain to aid in appropriate diagnosis, triage, referral, and treatment.  Neurologic and psychiatric disorders reviewed will include chronic pain syndrome, TBI, chronic migraine, fibromyalgia, Parkinsons disease, anxiety and depression.