We further elevated the polymeric application of aza-diarylethene 9 by using it in two different capacities for the same material. First, MA was polymerized with 9 as photoinitiator in lower concentrations to yield almost colorless, transparent poly-(methyl)-acrylate (PMA). Second, after finishing the polymerization, 9 was added anew to the material as a photochromic component. When analyzing the corresponding UV/vis changes in the transparent material, a somewhat similar behavior to polar protic MeOH solution is observed. In MeOH, 9 undergoes a concomitant ring closure, aromatization, and charge separating zwitterion formation upon irradiation. The resulting closed isomer Z-9 is colored yellow with significant absorption increase in the visible region around 450 nm. In this PMA application, the UV/Vis spectra revealed photoisomerization after irradiating the sample with light of 275 nm similar to the experiments in solution (Figure ). Also a broad absorption band appeared around 450 nm indicating the zwitterionic species, which was also visible by the light yellow color change (Figure ). The zwitterionic state is more pronounced in PMA (Figure ), than it is in PS (Figure ) which can be explained by the polarity and rigidity difference of the two polymers.