ABSTRACT Difficulties experienced with the use of meridional magnifying lenses at axis 90 combined with meridional magnifying lenses at axis 180 in space eikonometry are discussed. A modification of the space eikonometer technique by the use of overall combined with meridional at axis 180 is proposed. A simplified table is presented for the conversion of space‐eikonometer findings obtained by this technique to the specifications of the oblique meridional aniseikonic correction. The modified procedure is justified on the basis of the mathematical and physiological equivalence of the several forms of designating the aniseikonic ratio. It is claimed for this method that it improves testing procedure, increases the accuracy of the test, and enables the clinician to readily interpret raw findings in terms of the final aniseikonic correction.
Harold M. Fisher (1949) studied this question.