[A comparative study of the reflective and apperceptive refractions (author's transl)]

Reflective (objective) refraction differs basically from apperceptive (subjective) refraction in that it excludes conscious seeing from the measuring procedure. As a result limits can be established for the subjective acceptability of refraction values with automatic or manual refractometers. In a comparative study of 50 cases the correction values obtained with the manual refractometer PR 50 (Rodenstock) and the automatic refractometers Dioptron (Coherent Radiation) and Auto-refractor 6600 (Acuity Systems) were compared with the results of conventional subjective refraction. Criterion for this comparison was the visual acuity achieved with the correction values. In 55% of the cases the same, in some cases even better visual acuity was achieved than with subjective refraction. In the other 45% a direct comparison of the reflective and the subjective refraction values shows which component (sphere, cylinder) of the refractometer correction value leads to a lower visual acuity.