The visual sys­tem is a com­plex and mul­ti­fac­to­r­ial enigma, parts of which we are just begin­ning to explore. When we refract patients (check them for new glasses or con­tact lens pre­scrip­tions), we take pre­cise mea­sure­ments of their visual acu­ity, func­tion, and defo­cus (among other aspects). The val­ues we come up with are all impor­tant, but what’s really impor­tant … Con­tinue read­ing →