[Biometrics and aphakia (author's transl)].

The combination of long axis measurement (ultrasonic) and corneal measurement is well adapted to determination of refraction in aphakia. In a group of 35 persons the results of this method were compared with subjective refraction measurement and skiascopy. "Ultrasonic" refraction was less than one dioptre different from subjective refraction in 62% of cases. We found that ultrasonic-determined axis length was consistently 0.4 mm shorter than the axis length calculated from subjective refraction measurements. The clinical application and accuracy of the method are described. With the help of a nomogram one can read off the refraction, when axis length and corneal curvature are known.