A head mounted display system can include a camera, at least one waveguide, at least one coupling optical element that is configured such that light is coupled into said waveguide and guided therein, and at least one out-coupling element. The at least one out-coupling element can be configured to couple light that is guided within said waveguide out of said waveguide and direct said light to said camera. The at least one coupling element may comprise a diffractive optical element having optical power. Additionally or alternatively, the at least one coupling optical element may have a coupling area for coupling light into said waveguide having an average thickness in a range from 0.1 to 3 millimeters across and/or may have a slit shaped coupling area.