Optical guidance device and method of manufacturing such a device

An ocular-vision optical system comprising an optical guidance device for optical guidance of a light beam transporting an image, said optical guidance device comprising:

• a first part, made from a transparent material, comprising an extraction section comprising at least one microstructure, situated on a surface of said first part;
• a second part, made from a material substantially identical to that of said first part, comprising a section, comprising on a surface thereof at least one microstructure with a form complementary to that or those of said extraction section;
• wherein the optical guidance device is such that said first part propagates the light beam by successive total internal reflections inside said first part and wherein each microstructure comprises a flat surface enabling rays of the light beam propagated by successive reflections in said first part and striking said flat surface to emerge from the optical guidance device;
• and
• wherein said optical guidance device further comprises:
• a layer of adhesive extending over a part of the surfaces of said first and second parts assembling them so that every microstructure of said extraction section is separated from its complementary microstructure by a transparent medium of substantially constant thickness.