A reduced-pressure medical treatment system for treating a tissue site on a patient includes a medical drape that has an holographically-formed polymer dispersed liquid crystal (H-PDLC) device that changes visual appearance when experiencing strain. The change in visual appearance of the H-PDLC device allows identification of the existence of strain and may allow a quantitative assessment of the range of stress involved. In other aspects, a dressing conduit connector, canister, and reduced-pressure interface use a holographically-formed polymer dispersed liquid crystal (H-PDLC) device to help determine the existence and perhaps the amount of stress experienced. Other systems, methods, and devices are presented.