Device for viewing stereoscopic 3d images

Device (1) for viewing stereoscopic 3D images using an electronic device (50) comprising a screen display (51), which device (1) comprises

• a head fastening means (10), arranged to fasten the device (1) to a user's (70) head (71) so that the device (1) assumes a mounted position on said head (71);
• a holder part (40) arranged to receive and removably accommodate the electronic device (50) in an accommodation space (42);
• a lens part (20) arranged to focus light from said screen display (51) to the eyes of the user (70) when the device (1) is in said mounted position and the electronic device (50) is arranged in said accommodation space (42);
• as well as
• a distance part (30), arranged to provide a predetermined distance (D1) between the lens part (20) and the screen display (51),
• wherein the lens part (20) is arranged to, when the device (1) is in said mounted position, provide a first image (52a) from a first part (52) of the screen display (51) to a first eye of the user (70), and a second image (53a) from a second part (53) of the screen display (51) to a second eye of the user (70), which first (52) and second (53) parts are distinct from each other, wherein the holder part (40) is supported in relation to the lens part (20) by the distance part (30), the distance part (30) is arranged to be reversibly collapsible along a collapsing direction (D2), which collapsing direction (D2) extends between the holder part (40) and the lens part (20), from a fully expanded state, in which the lens part (20) is arranged at said predetermined distance (D1) from the screen display (51), to a contracted state, in which the lens part (20) is arranged closer to the holder part (40) than what is the case in said fully expanded state, and wherein the outer dimensions of the device (1) decrease as a result of such collapse.