Retained foreign bodies were found in 731 of 3,882 eyes of soldiers studied at the Army Institute of Pathology during World War II. All globes with penetrating wounds were examined roentgenologically and were searched for foreign bodies. In many instances the particles were so small or so deeply embedded in organizing hemorrhage or inflammatory membrane that they were not recovered from the gross specimens and became visible only on microscopic examination. These could not be subjected to the magnet test, but sections containing them were stained with prussian blue.
A look at the past .... Arch Ophthalmol. 2007;125(9):1263. doi:10.1001/archopht.125.9.1263