My 12 y/o neice has been hospitalized due to an extreme pain in her upper body probably caused by arthritis (she has beed already diagnosed with Arthritis but we're not 100% sure if this new pain is related to her condition). The pain does not go away and all of the sudden her eyes have crossed and she now has double vision. She was given morphine for the extreme pain. Can the crossed eyes be a side effect of the pain killer? Or is it possible that the pain and the crossed eyes are symptoms of something else?