A backlight unit comprising: a light guide configured to receive light at a first light interface located at an end of the light guide and output light via a second light interface located at a face of the light guide; a plurality of light sources configured to inject light into the light guide at the first light interface and comprising a first subset of the plurality of light sources configured to emit light in a first range of acceptance angles and a second subset of the plurality of light sources configured to emit light in a second range of acceptance angles; and an angle-dependent diffuser layer (214, 600) characterized in that said angle-dependent diffuser layer (214,600) comprises: a first graded index film (602, 608, 614) configured to receive light from the second light interface of the light guide, homogenize received light that is incident on the first graded index film (602, 608, 614) from within said first range of acceptance angles and not homogenize light incident on the first graded index film (602, 608, 614) from outside of the first range of acceptance angles, and direct the homogenized light toward a first eye box (502, 506); and a second graded index film (602, 608, 614) configured to receive light from the second light interface of the light guide, homogenize received light that is incident on the second graded index film (602, 608, 614) from within said second range of acceptance angles and not homogenize light incident on the second graded index film (602, 608, 614) from outside of the second range of acceptance angles, and direct the homogenized light from the second graded index film (602, 608, 614) toward a second eye box (502, 506) having a different location than the first eye box (502, 506). a light guide configured to receive light at a first light interface located at an end of the light guide and output light via a second light interface located at a face of the light guide; a plurality of light sources configured to inject light into the light guide at the first light interface and comprising a first subset of the plurality of light sources configured to emit light in a first range of acceptance angles and a second subset of the plurality of light sources configured to emit light in a second range of acceptance angles; and an angle-dependent diffuser layer (214, 600) characterized in that said angle-dependent diffuser layer (214,600) comprises: a first graded index film (602, 608, 614) configured to receive light from the second light interface of the light guide, homogenize received light that is incident on the first graded index film (602, 608, 614) from within said first range of acceptance angles and not homogenize light incident on the first graded index film (602, 608, 614) from outside of the first range of acceptance angles, and direct the homogenized light toward a first eye box (502, 506); and a second graded index film (602, 608, 614) configured to receive light from the second light interface of the light guide, homogenize received light that is incident on the second graded index film (602, 608, 614) from within said second range of acceptance angles and not homogenize light incident on the second graded index film (602, 608, 614) from outside of the second range of acceptance angles, and direct the homogenized light from the second graded index film (602, 608, 614) toward a second eye box (502, 506) having a different location than the first eye box (502, 506).