The causes of dry eye, they are as follows:  Rheumatoid arthritis  P syndrome Ankylosing spondylitis Systemic Lupus Erythematosus Wegener’s granulomatosis Herpes Zoster Ophthalmicusgout Syphilis Corneal dystrophy Human immunodeficiency virus after Lasik Irritable bowel syndrome Drugs like prostaglandin analogue