FIG. 2.

Upper tarsal conjunctival zones used for scoring F in the FPC system. “Zones are defined by two imaginary lines which, as viewed on the everted tarsal surface, are approximately parallel with the upper tarsal border and curve upward towards their lateral extremities… Zone 1 includes the entire upper tarsal border and adjacent lateral tarsal surface; zone 2 occupies the area between zones 1 and 3 and extends to the lateral quarters of the lid margin; zone 3 includes the tarsal conjunctiva adjacent to the central half of the lid margin and, at its center, covers just less than half the vertical extent of the tarsal surface” (reference 53, p. 14). Modified by Matthew Burton and reproduced with the permission of M. Burton and the World Health Organization.