Fig. 1.
The physiological response of a cone cell to light produces nanometer OPL changes in its OS, which we detect with AO-OCT. (A) Schematic shows the axon, soma, inner segment (IS), and OS of a cone cell, and the underlying retinal pigment epithelium (RPE) cell that ensheathes it. The cone cell is stimulated with a visible flash during AO-OCT imaging, and the resulting phase and OPL changes are defined mathematically, as shown. The phase difference, ϕOS, is between the two bright reflections at opposing ends of the cone OS, which are labeled as IS/OS and COST (cone OS tip). (B) Normalized spectra of the three light sources that stimulate the cones are shown with the normalized sensitivity functions of the three cone types that are sensitive to short- (S), medium- (M), and long- (L) wavelength light (31).