Hudson-Stähli's iron line in the cornea. Occurrence in 1968 and in 1988

Examination of 700 persons in 1968 showed presence of Hudson-Stähli's iron line in 29%. A similar examination by the same author 20 years later revealed a significantly lower occurrence (18%) and fewer cases of binocular occurrence (70% against 43%). The line is most often horizontal. If oblique, it generally passes from the upper nasal to the lower temporal region.