A user wearable optical display system comprising: a user attachment section for detachably mounting said user wearable optical display system to a head of a user; a partially transmissive partially reflective lens, coupled with said user attachment section, and configured to be facing at least one eye (278R, 278L) of said user; and an electro-optical unit coupled with at least one of said user attachment section and said partially transmissive partially reflective lens, said electro-optical unit comprising: a processor; and a light projection unit coupled with said processor, said light projection unit includes an image generator, a first lens, a second lens, a third lens, a fourth lens, a curved mirror, and a folding mirror, said light projection unit is configured to transmit light beams onto said partially transmissive partially reflective lens; wherein said image generator is configured to generate and irradiate light beams, said folding mirror is configured to fold said light beams traveling an optical path from said image generator through said first lens, then through said second lens, then reflect from said curved mirror, and then pass again through said second lens and said first lens thereby refracting twice through said first lens and said second lens, wherein said folding mirror is disposed at a position along said optical path between said image generator and said first lens, wherein said electro-optical unit is configured to be positioned with respect to said user attachment section such that when said user wearable optical display system is mounted on said user, said electro-optical unit is located at the glabellar region of said user thereby providing an unobstructed field of regard to said user, wherein said folding mirror facilitates minimization of spatial dimensions of said light projection unit enabling said electro-optical unit to be located at said glabellar region. a user attachment section for detachably mounting said user wearable optical display system to a head of a user; a partially transmissive partially reflective lens, coupled with said user attachment section, and configured to be facing at least one eye (278R, 278L) of said user; and an electro-optical unit coupled with at least one of said user attachment section and said partially transmissive partially reflective lens, said electro-optical unit comprising: a processor; and a light projection unit coupled with said processor, said light projection unit includes an image generator, a first lens, a second lens, a third lens, a fourth lens, a curved mirror, and a folding mirror, said light projection unit is configured to transmit light beams onto said partially transmissive partially reflective lens; a processor; and a light projection unit coupled with said processor, said light projection unit includes an image generator, a first lens, a second lens, a third lens, a fourth lens, a curved mirror, and a folding mirror, said light projection unit is configured to transmit light beams onto said partially transmissive partially reflective lens; wherein said image generator is configured to generate and irradiate light beams, said folding mirror is configured to fold said light beams traveling an optical path from said image generator through said first lens, then through said second lens, then reflect from said curved mirror, and then pass again through said second lens and said first lens thereby refracting twice through said first lens and said second lens, wherein said folding mirror is disposed at a position along said optical path between said image generator and said first lens, wherein said electro-optical unit is configured to be positioned with respect to said user attachment section such that when said user wearable optical display system is mounted on said user, said electro-optical unit is located at the glabellar region of said user thereby providing an unobstructed field of regard to said user, wherein said folding mirror facilitates minimization of spatial dimensions of said light projection unit enabling said electro-optical unit to be located at said glabellar region.