An apprentice working in a metal fabrication factory consulted me some time ago because he had felt something “go into his eye” while grinding. He had felt the discomfort would “clear up within a few days”, but the pain and redness in the eye had since increased significantly. Protective eyewear had not been worn at the time as it was “just a quick job”.
Examination of the eye under the microscope revealed the source of the discomfort to be a piece of metal embedded in the cornea (clear layer in front of the pupil) surrounded by a ring of rust as can be seen in the picture on the right.
Removing this is relatively straightforward, but requires a sterile instrument and is best performed under a microscope especially designed for examining eyes. However, removal of the rust ring is more difficult as the rust invades the surrounding tissue and can only be removed by excising a small amount of this tissue (2nd picture). This results in a small scar which is not serious if it is close to the edge of the cornea. However, vision can be seriously affected if it is in the centre of the pupil.
Using protective eyewear at all times can prevent these types of injuries. However, any foreign body entering the eye should be removed without delay to prevent or reduce the risk of complications.