Functional Determination of Rod Free Area of Human Retina
1956 Volume 64 Issue 2 Pages 169-178
Details
1956 Volume 64 Issue 2 Pages 169-178
The distribution of the rod process was studied by the method of the electrical stimulation of the eye.
1) Experiment 1
The fovea of the human retina was exposed to circular patches of various sizes illuminated by spectral light of 510mμ and ζ-intensity curves of the rod process were obtained. Two types of ζ-intensity curves were distingushed. In the type I ζ was a simple linear function of the logarithm of the intensity, and in the type II ζ remained constant over a certain range of lower intensities. It was shown that the latter behavior of type II is based on the rod process. Utilizing this property the rod free area was determined. 2) Experiment 2 The spatial distribution of the magnitude of ζ was obtained, using i patch of small size and thus the rod free area was directly determined.
3) The results of these experiments agreed with each other. Rods lo not appear at all in a central area of 40' in diameter in visual angle and begin to appear in an area of 50' in normal subjects. In color-blind subjects, protanope and deuteranope, rods do not appear at all in an area of 18' and appear first in an area of 25'.
4) These results well agree with the rod free area determined histo-logically by Oesterberg.
The author wishes to express his hearty thanks to Prof. K. Motokawa for his kind guidance and encouragement.
