tokens: In cross - section I , 219 persons ( 6 . 0 % ) had missing or ungradable Neitz photographs , leaving 3435 with photographs available for cortical cataract and PSC assessment , while 1153 ( 31 . 6 % ) had randomly missing or ungradable Topcon photographs due to a camera malfunction , leaving 2501 with photographs available for nuclear cataract assessment .