CALCA and keratoconus: There, KC output is integrated by smaller populations of extrinsic neurons (called α- and β-lobe neurons, respectively; Figure 1A) with large, planar dendritic trees which intersect KC-axon bundles at neat right angles (Li and Strausfeld, 1997; MacLeod et al., 1998; Cassenaer and Laurent, 2007), suggesting potential integration of precisely timed spikes over a wide KC-subpopulation.