Fig. (7) (A) Extensive visual field defect involving superior hemifield (B) Paracentral visual field defect. Both defects are classified as severe by Hoddap Parish and Anderson criteria (any point within central 5°with sensitivity less than or equal to 0 dB). Using USP System visual field A would be described as S59/ 5/2B and visual field B as E91/ 5/ 1A, providing clear differentiation between them.