On the Electrical Excitability of the Eye in Congenital Achromatopsia (with Motokawa's Method)

Abstract

The electrical excitability of the eye and the time courses of changes in the electrical excitability after the illumination of 2 seconds or a flash of light were investigated for white light in a normal subject and a case of congenital achromatopsia, which belonged to the so-called rod-mono-chromat in type.
The results obtained are as follows:
1. The change in the achromat's electrical excitability after light-adaptation is much slighter than that of the normal subject.
2. The data presented, so far as the photopic vision is concerned, are consistent with the classical view that the cone-process is lacking in the achromat, and that vision is mediated entirely by rod-process. It merits attention, however, that the optimum conditions in which the rod-process of the achromat is most evidently at work are considerably differnt from those of normal subjects.
3. Another process besides the rod-one has been found in the retina of the achromat. The process has some properties characteristic of the cone-process and is at work only at lower intensities of illumination.
The work reported here was done under the auspices of Prof. Y. Kurachi, and much of the work was suggested by Prof. K. Motokawa. We wish to ex-press our sincerest thanks to them for their valuable advices and guidances.