An optical system, comprising: a light-transmitting substrate having a plurality of surfaces including at least a first and a second major external surface, the light-transmitting substrate configured to guide coupled-in light waves indicative of a scene image between the major external surfaces (26, 28) of the light-transmitting substrate by internal reflection, and the light-transmitting substrate further configured to couple the light waves out of the light-transmitting substrate; a lens arrangement external to the light-transmitting substrate including at least a first lens located next to one of the major external surfaces of the light-transmitting substrate, the first lens focusing at least one image, corresponding to at least one of light waves passed through the light-transmitting substrate, and the light waves guided between the major external surfaces (26, 28) of the light-transmitting substrate, to at least one distance for viewing by an eye of a viewer; and characterized by having at least one transparent air gap film including a base and a hyperfine structure constructed on the base, the hyperfine structure defining a relief formation and having a pitch shorter than wavelengths of the light waves guided between the major external surfaces (26, 28) of the light-transmitting substrate, wherein the air gap film is deployed with the base optically coupled to a portion of the first lens and the relief formation facing one of the major external surfaces of the light-transmitting substrate to define an interface plane, and wherein the light waves indicative of a scene image coupled inside the light-transmitting substrate, impinging on the major external surfaces (26, 28) of the light-transmitting substrate at oblique angles, are internally reflected from the interface plane. a light-transmitting substrate having a plurality of surfaces including at least a first and a second major external surface, the light-transmitting substrate configured to guide coupled-in light waves indicative of a scene image between the major external surfaces (26, 28) of the light-transmitting substrate by internal reflection, and the light-transmitting substrate further configured to couple the light waves out of the light-transmitting substrate; a lens arrangement external to the light-transmitting substrate including at least a first lens located next to one of the major external surfaces of the light-transmitting substrate, the first lens focusing at least one image, corresponding to at least one of light waves passed through the light-transmitting substrate, and the light waves guided between the major external surfaces (26, 28) of the light-transmitting substrate, to at least one distance for viewing by an eye of a viewer; and characterized by having at least one transparent air gap film including a base and a hyperfine structure constructed on the base, the hyperfine structure defining a relief formation and having a pitch shorter than wavelengths of the light waves guided between the major external surfaces (26, 28) of the light-transmitting substrate, wherein the air gap film is deployed with the base optically coupled to a portion of the first lens and the relief formation facing one of the major external surfaces of the light-transmitting substrate to define an interface plane, and wherein the light waves indicative of a scene image coupled inside the light-transmitting substrate, impinging on the major external surfaces (26, 28) of the light-transmitting substrate at oblique angles, are internally reflected from the interface plane.