Further Evaluation of an Apparent Failure of the Photoreceptor Alignment Mechanism in a Human Observer

• A human subject whose photoreceptors were deduced to be oriented toward a common point near the center of the eyeball rather than toward a common point within the pupil was reexamined three years after the original testing. The photoreceptors were still found to be oriented in the aforementioned anomalous fashion, as deduced from the peak locations of Stiles-Crawford (S-C) functions measured at various retinal locations, as before. Patching the eye for a week caused little or no flattening of the S-C functions.