A 32-year-old woman wakes with sharp pain in her right eye. Initially she felt as if she had a piece of glass in her eye. Now her eye feels sandy and dry but is slowly improving. She reports no history other than a remote corneal abrasion from a tree branch several years ago.

A reformed drug addict presents with acute pain, lid erythema, and crippling photophobia in his right eye.

After a recent visit to another eye doctor, a 67-year-old man presents with recurrent episodes of bilateral conjunctivitis, crusting, and foreign-body sensation.