An optical element for a display device which can be placed onto the head of a user and generates an image, which element has a front side and a rear side, an input portion and an output portion spaced apart from the input portion and a light-guiding channel, which is suitable for guiding bundles of light of pixels of the generated image that are input into the optical element via the input portion of the optical element in the optical element to the output portion, from which they are output from the optical element, wherein the output portion has an optically effective structure which brings about a deflection of the bundles of light for output, and wherein the optical element has a first part of a first material, which comprises the optically effective structure, and the optical element has a second part of a third material, wherein the two parts (19, 22) are connected to one another with an adhesive composition of a second material, wherein the first material comprises one or more cycloolefin polymers and the proportion of the one or more cycloolefin polymers is at least 95% by weight based on the total weight of the first material; characterized in that the first and third materials are different from one another, wherein the second and third materials comprise in each case at least one organic polymer, the polymer(s) of the third material make up at least 95% by weight of the third material, the third material is not a cycloolefin polymer and the organic polymer of the third material is polyurethane, and wherein the differences in the refractive index for at least one wavelength of between 380 nm and 800 nm between the first material and the second material and between the second material and the third material are in each case ≤ 0.02. has a front side and a rear side, an input portion and an output portion spaced apart from the input portion and a light-guiding channel, which is suitable for guiding bundles of light of pixels of the generated image that are input into the optical element via the input portion of the optical element in the optical element to the output portion, from which they are output from the optical element, wherein the output portion has an optically effective structure which brings about a deflection of the bundles of light for output, and wherein the optical element has a first part of a first material, which comprises the optically effective structure, and the optical element has a second part of a third material, wherein the two parts (19, 22) are connected to one another with an adhesive composition of a second material, wherein the first material comprises one or more cycloolefin polymers and the proportion of the one or more cycloolefin polymers is at least 95% by weight based on the total weight of the first material; characterized in that the first and third materials are different from one another, wherein the second and third materials comprise in each case at least one organic polymer, the polymer(s) of the third material make up at least 95% by weight of the third material, the third material is not a cycloolefin polymer and the organic polymer of the third material is polyurethane, and wherein the differences in the refractive index for at least one wavelength of between 380 nm and 800 nm between the first material and the second material and between the second material and the third material are in each case ≤ 0.02.