Abstract: A blocking material composition, an essentially homogeneous mixture of(a) 80-90 weight percent of an ethylene derived hydrocarbon polymer having a molecular weight of 2600, a melting point of 51.degree. C. and a density of 0.79 g/cc at 93.degree. C.,(b) 10-15 weight percent of a thermoplastic, low molecular weight aliphatic hydrocarbon resin derived from mixed monomers of petroleum origin having a softening point of 98.degree.-102.degree. C., a specific gravity of 0.948 at 25.degree. C., an acid number <1, a molecular weight of 1985 and(c) 1-3 weight percent of an ethylene/vinyl acetate copolymer having a vinyl acetate content of 18 percent by weight, a melt index of 150 g/10 min, a density of 937 g/cm.sup.3 at 23.degree. C. and a softening point, ring and ball, of 99.degree. C. Also disclosed is a lens block of the blocking material and method for securing an ophthalmic lens to one surface of a lens block by applying to one surface of said lens block a molten blocking material composition.