Projection screens

A method of making an optical element such as a screen or display with preferential light scattering directions, the method comprising:

• forming a polymeric composition comprising a first polymeric material and a second polymeric material dispersed within the first polymeric material, wherein an index of refraction of the first polymeric material differs by at least 0.01 from an index of refraction of the second polymeric material;
• and
• dispensing the polymeric composition on a substrate, wherein the dispensing results in the second polymeric material forming a plurality of elongated structures within the first polymeric material, each elongated structure having a major axis with the major axes of the elongated structures being substantially aligned.

An optical system comprising:

• an illumination source for providing light,
• a screen having a incident surface for receiving light from the illumination source and a viewing surface, the screen comprising:
• a first polymeric material and a dispersed phase material disposed as a plurality of elongated structures within the first polymeric material, each elongated structure having a major axis, wherein the major axes of the elongated structures are substantially aligned and the dispersed phase material has an index of refraction that differs by at least 0.01 from an index of refraction of the first polymeric material, and wherein the elongated structures are sized, shaped and positioned to asymmetrically diffuse light from the illumination source.