An apparatus for use in a near eye display device comprising: a first pair of in-coupling diffraction gratings having a first repeated diffraction spacing, d 1 ; a second pair of in-coupling diffraction gratings having a second repeated diffraction spacing, d 2 ; a first out-coupling diffraction grating and a second out-coupling diffraction grating , wherein each of the first and second out-coupling diffraction gratings comprises: a first region having the first repeated diffraction spacing, d 1 , configured to out-couple light of a first wavelength to a user's eye , and a second region adjacent to the first region and having the second repeated diffraction spacing, d 2 , different from the first spacing, d 1 , configured to out-couple light of a second wavelength to the user's eye ; wherein the first region of the first out-coupling diffraction grating is superposed on and aligned with the second region of the second out-coupling diffraction grating ; wherein the second region of the first out-coupling diffraction grating is superposed on and aligned with the first region of the second out-coupling diffraction grating ; wherein the first pair of in-coupling diffraction gratings are configured to direct light to the first region of respective ones of the first and second out-coupling diffraction gratings ; and wherein the second pair of in-coupling diffraction gratings are configured to direct light to the second region of respective ones of the first and second out-coupling diffraction gratings . a first pair of in-coupling diffraction gratings having a first repeated diffraction spacing, d 1 ; a second pair of in-coupling diffraction gratings having a second repeated diffraction spacing, d 2 ; a first out-coupling diffraction grating and a second out-coupling diffraction grating , wherein each of the first and second out-coupling diffraction gratings comprises: a first region having the first repeated diffraction spacing, d 1 , configured to out-couple light of a first wavelength to a user's eye , and a second region adjacent to the first region and having the second repeated diffraction spacing, d 2 , different from the first spacing, d 1 , configured to out-couple light of a second wavelength to the user's eye ; a first region having the first repeated diffraction spacing, d 1 , configured to out-couple light of a first wavelength to a user's eye , and a second region adjacent to the first region and having the second repeated diffraction spacing, d 2 , different from the first spacing, d 1 , configured to out-couple light of a second wavelength to the user's eye ; wherein the first region of the first out-coupling diffraction grating is superposed on and aligned with the second region of the second out-coupling diffraction grating ; wherein the second region of the first out-coupling diffraction grating is superposed on and aligned with the first region of the second out-coupling diffraction grating ; wherein the first pair of in-coupling diffraction gratings are configured to direct light to the first region of respective ones of the first and second out-coupling diffraction gratings ; and wherein the second pair of in-coupling diffraction gratings are configured to direct light to the second region of respective ones of the first and second out-coupling diffraction gratings . <EOS>