Clinical grading of corneal staining of non-contact lens wearers.

To distinguish normal from pathological corneal fluorescein staining requires knowledge of background levels of staining among otherwise healthy individuals. Corneal staining of 102 non-contact lens wearing subjects was assessed using a photographic grading scale that uses a generic (0 to 4) scale to score corneal staining. Some degree of corneal staining was found on 79% of the corneas. Low inter-observer variability suggests that the corneal staining grading scale can be used successfully with decimal rather than integer scale increments.