OPTICAL FILM

An optical film includes a light transmissive substrate having a first surface and a second surface opposite thereto, strip protrusions on the first surface, and protruding structures on crest lines of the strip protrusions. Each strip protrusion has two strip surfaces. Each protruding structure has a protruding end protruding from the crest line of the corresponding strip protrusion and two wing portions on the strip surfaces of the corresponding strip protrusion. Each wing portion extends from the protruding end to a place between the crest line and a valley line. A length of the protruding structure parallel to an extension direction of the crest line is L, a width of the protruding structure perpendicular to the crest line is W, and L/W 1.2. At least one of a moiré phenomenon, a local adherence phenomenon, a scratching phenomenon, and a wearing phenomenon with other optical devices is effectively mitigated.