Disclosed is an optical disk, card or media which comprises: a) a plurality of data structures that are readable by the interrogating beam of light; and b)a composition on or in the optical disk, card or media disposed so that when the optical disk, card or media is used in the optical read-out system, the interrogating beam of light passes through the composition before or after contacting some or all of the data structures. The composition comprises a polymeric matrix with an organometallic complex dissolved therein or with metal, transition metal, metal oxide or transition metal oxide nanoparticles uniformly dispersed therein. The composition is substantially transparent to the interrogating beam and/or is substantially colorless. Alternatively, the composition comprises a solid polymeric matrix with an olefinic compound dissolved or uniformly dispersed therein wherein double bond in the olefinic compound undergoes oxidative cleavage promoted by a transition metal catalyst and a thiophenol or a catalytic amount of a thiyl radical and wherein the composition is substantially transparent to the interrogating beam and/or is substantially colorless.