This is a piece of metal in the eye, and is commonly caused while grinding or working on machinery. Small pieces of metal can fly or fall into the eye, and for some reason, metal likes to stick to the clear cornea. When this happens, the metal will embed into the eye and rust into place (the tear film is rather salty). Metal in the eye is painful and if not removed promptly, can lead to infection and scarring with potential long-term visual consequences. Sometimes, a piece of metal can be wiped off with a cotton swab, but often it requires more aggressive debridement. Typically, we’ll numb the eye with topical anesthesia drops. Then, a small metal pick (like a needle, but not sharp) is used to wipe the piece off the cornea. If there is residual rust or metal fragments, this may need to be removed with a high-speed rotary tool like a microscopic dremel tool. This is all done sitting up at the exam chair, and while most people are understandably nervous, the whole procedure is surprisingly pain-free. Afterwards, we treat with antibiotics and recheck the eye over the next week to make sure no infection occurs. If, based on history and exam findings, we are concerned about a piece of metal actually penetrating the eye … then a more involved examination is done. This may require a CAT scan to rule out metal pieces inside the eyeball.
Here is a video showing the removal of metal from the eye:
length: 1:03 minutes