| http://www.w3.org/ns/prov#value | - A photochromic composition comprising (a) 100 parts by weight of a di(meth)acrylate compound represented by the formula (I): ##STR1## wherein R1 s each independently represent hydrogen or methyl, R2 s and R3 s each independently represent alkylene having 1 to 4 carbon atoms, X represents halogen other than fluorine, Y represents oxygen or sulfur, and m is an integer of 0 to 4, and (b) 0.01 to 5 pa
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