One embodiment of the invention comprises a simplified light-weight head
mounted displays comprising an off-axis combiner and imaging optics
defining an optical path. The imaging optics comprises a lens group
comprising a plurality of lenses in the optical path. The lens group has
a first optical axis. Each of said plurality of lenses have optical axes
collinear with the first optical axis. The imaging optics further
comprises a single lens element in the optical path having a second
optical axis that is different from the first optical axis. The single
lens element has positive optical power and is the only lens element in
the optical path between the lens group and the combiner that has an
optical axis collinear with the second optical axis.