Disclosed are methods for forming a double-sided optical sheet, and a vehicle lamp assembly having the double-sided optical sheet integrated therein. A first optical pattern is imprinted on a first side of a material, and a second optical pattern is imprinted on a second side of the material, opposite the first side. The first and second optical patterns are thereby formed on opposing sides of the same sheet. When oriented adjacent a light source, the double-sided optical sheet homogenizes light emitted from the light source. For a light source having a plurality of lighting elements, the double-sided optical sheet is configured to blend light emitted from the plurality of lighting elements to form one homogenous beam of light output resulting from a single light-modifying member.