The reason a piece of metal can sit undetected inside a human eye for a decade is not that it hurts too much to examine. It is that it often does not hurt much at all.
That is the central finding of a multicenter study of 18 eyes in which an intraocular foreign body was missed or diagnosed late. Patients frequently arrived with good vision and a corneal or scleral wound that had already sealed itself, leaving little for an emergency clinician to find. The work was led by researchers at Massachusetts Eye and Ear and Harvard Medical School, with collaborators at SUNY Upstate, the University of Iowa, Bascom Palmer, and two other centers, and was published in the Journal of VitreoRetinal Diseases.
