Experimental results relating mechanical strain and visible‐light scattering to ferroelectric domain switching as the electric displacement of lead lanthanum zirconate titanate (PLZT) 7/65/35 is switched through the hysteresis loop are presented. Both strain and light scattering measurements were made before and after storing a photoinduced space‐charge fieldESCin first a radially constrained and then an unconstrained PLZT disc. The results of these measurements tend to clarify the role ofESCin photoferroelectric information storage. Specifically,ESCis nonvolatile and cannot be reoriented by an externally applied switching field alone. The thresholds for domain switching in the bulk of the PLZT are lowered in the direction ofESC, but they are increased to the extent of preventing some domain switching antiparallel toESC.