[Lens caused shifts in color co-ordinates measured on the ocular fundus (author's transl)]

Changes in certain areas of the ocular fundus are frequently accompanied by changes in the spectral distribution of the reflected light. In many diseases of the ocular fundus, it is desirable to have an objective difinition of the color of the fundus during a particular phase of the disease. An instrument designed by Carl Zeiss, Oberkochen, West Germany, provides a satisfactory solution to the problem of measuring color on the ocular fundus. Transformational equations make it possible to convert the measurement parameters obtained by visual comparison into standardized color measurment values. The measurement error is slighter than necessary for clinical examinations. The possible influence of the ocular lens's own color on the color co-ordinates measured on the fundus was examined. Measurement of fundus color in three suitable situations showed no differences in color coordinates on the fundus between aphakic eyes of younger patients and eyes containing lenses. Incipient cataracts cause only a slight shift of the color co-ordinates. More marked cataracts cannot lead to erroneous interpretation of the measurement results, since measurement with this method is no longer technically possible in such cases.