We have now extended those experiments to partial bleaches. Ganzfeld bleaches were delivered using intense flashes from this stimulator, or using steady illumination from a small stimulator that fitted over the eye. Ethical approval was given by the Cambridge Human Biology Ethics Committee, and informed consent was obtained from each subject. These experiments provide evidence of the direct role that human rod photoreceptors play in psychophysical dark adaptation recovery.
Traces are arbitrary curves fitted to the results for individual bleaching levels.