A display device has a display to generate a real image. An optical system has lenslets,
each generating a virtual sub-image from a respective partial real image on the display, by
each lenslet projecting light from the display to an eye position. The sub-images combine to
form a virtual image viewable from the eye position. At least one of the lenslets is an “RXIR”
lenslet, in which the light rays from the display to the eye position are deflected sequentially
at least four times by a refraction (R), a reflection (X), a total internal or metallic reflection (I) …