One embodiment of the invention comprises a simplified light-weight head
mounted displays comprising an off-axis combiner and a pair of plastic
lenses. One of the lenses is a rotationally symmetric optical element and
one of the lens is a non-rotationally symmetric optical element. This
non-rotationally symmetric optical element comprises first and second
lens surfaces that are tilted and decentered with respect to each other.
One of these first and second lens surfaces may also include diffractive
feature to provide a diffractive or holographic optical element for color
correction.