Comparison of six colour vision tests for occupational screening.

Screening of red-green colour vision defects was done for 52 school children (22 boys and 30 girls) and 231 trade school students (226 boys and 5 girls) with three different kinds of pseudo-isochromatic plates: Ishihara (1983), Boström-Kugelberg (1972), and Standard Pseudoisochromatic Plates part 1 (SPP 1) 1978, and with three different kinds of vision screeners: Keystone View Model DVS 2, Bausch and Lomb Vision Tester, and Rodenstock Farbentestscheibe 3040.173. After these tests, each subject was examined with the Nagel Anomaloscope; this revealed 26 red-green defectives in the study group. Ishihara found 20/26 (76.9%), Boström-Kugelberg 24/26 (92.3%), and SPP 1 17/26 (65.4%) of the defectives. None of the normals were diagnosed as defectives with Ishihara or SPP 1. With Boström-Kugelberg four normals were diagnosed as defectives. Keystone found 24/26 (92.3%), Bausch and Lomb 26/26 (100%), and Rodenstock 25/26 (96.2%) of the defectives. But 9, 21, and 112 normals, respectively, were diagnosed as defective. In the present study, the Boström-Kugelberg and Ishihara plates as well as Keystone Vision Screener and Bausch and Lomb Vision tester came close to an effective screening test and could be recommended for screening red-green colour vision defects in occupational health care.