Abstract: An optical film assembly comprises a light redirecting film (110) having a first structured major surface (112) and a second, opposed major surface (114). An optical adhesive layer (120) is disposed on the second major surface of the light redirecting film. A light diffusion film (140) comprises a first major surface (142) comprising a light diffusion surface and a second, opposed major surface (144). A plurality of discrete optical decoupling structures (146) project from the light diffusion surface and contact the optical adhesive layer. An air gap (148) is defined between the first major surface of the light diffusion film and the optical adhesive layer. Embodiments of optical film assemblies described herein are useful, for example, for hiding optical defects and improving the brightness uniformity of light emitted by a light source.