Glu41Lys disrupts cone photoreceptor structure. Images from 0.5deg (A,B) and 2deg (C,D) reveal a disrupted mosaic in the patient with the p.Glu41Lys mutation (B,D) compared to that of a normal control (A,C). Near the fovea in the p.Glu41Lys retina (B), there was a sparse population of strongly waveguiding cones. In the parafoveal images of the same patient (D), there were a reduced number of cones and those present had severely diminished waveguiding. Normal-appearing rods are visible in-between the dark cone structures. Scale bar is 50 μm.