Photochromic materials have optical properties that change reversibly in response to irradiation. The benzospiropyran used in this work undergoes a transmission change of approximately 90% at 550 nm: however. a reasonable reaction rate for both the forward and reverse reaction is necessary for applications such as smart windows in buildings. The time constant for colorless spiropyrans to darken to the merocyanine form under ultraviolet radiation is of the order of 10 min, but the reverse reaction is very much slower. The objective of this work was to increase the reaction rate for the revere bleaching reaction. This was achieved by modifying the benzospiropyran in a poly(methyl methacrylate) matrix by the addition of one of seven porphyrins or phthalocyanines. We report second-order rate constants obtained from the slope of the reciprocal of the maximum absorption amplitude vs. time. These constants characterize the initial reaction rate. Data taken with an FTIR spectrometer showed that every porphyrin increased the initial reaction rate, with phthalocyanine showing the fastest reversion rate, 21-fold that of the unmodified benzospiropyran. One vanadyl phthalocyanine showed an eight-fold increase. The effect on the visible reaction rate was determined using vanadyl phthalocyanines, and a particular vanadyl phthalocyanine increased the initial reaction rate by a factor of approximately three.