Microreplicated optical film

A backlight for providing illumination along a first direction to a display disposed thereon, the backlight comprising:

• a plurality of spaced apart discrete light sources arranged in rows and columns of the light sources and configured to face the display;
• and
• an optical film comprising a structured first major surface opposite a second major surface, and a plurality of through-holes extending between the first and second major surfaces, disposed on the light sources and below and proximate a first plane, the optical film and the first plane configured to be disposed between the display and the light sources;
• wherein, when the optical film is disposed such that the first major surface faces the light sources, an average luminance in the first plane is smaller and a first brightness uniformity value is smaller, and when the optical film is disposed such that the second major surface faces the light sources, the first average luminance in the first plane is greater and the first brightness uniformity value is greater, wherein brightness uniformity value is calculated by dividing a maximum luminance value in the first plane by a minimum luminance value in the first plane.