The invention relates to a lighting device (1) for a for a motor vehicle headlight and/or for a rear light of a motor vehicle and/or for a signal light for a motor vehicle registration for generating at least two, in particular precisely two, light distributions, or for generating at least two, in particular precisely two different lighting functions, wherein the lighting device (1) comprises an optical element (2) and two light sources (30, 40) —a first light source (30) and a second light source (40), in particular LED light sources—wherein each of the light sources (30, 40) can be controlled independently of the other light source or sources, wherein the optical element (2) is formed from an optically transparent material, and wherein the optical element (2) has a light coupling region (10) and a light exit surface (11), and wherein light of the light sources (30, 40) which is introduced into the optical element (2) via the light coupling region (10) at least partially exits via the light exit surface (11), wherein the light coupling region (10) is formed from a central light coupling surface (100) and a lateral coupling surface (200) on the side, wherein the central light coupling surface (100) is opposite the light sources (30, 40), and wherein the lateral coupling surface (200) adjoins the central light coupling surface (100) in such a way that a recess is formed in the optical element (2), in or opposite which the light sources (30, 40) are arranged and into which the light sources (30, 40) emit their light, wherein the two light sources (30, 40) lie on a straight line (G) which runs in a vertical direction (R), which runs parallel to a vertical axis (Z), and wherein the first light source, seen in the vertical direction (30), lies above the second light source (40), and wherein the light coupling region (10) has two focal points (F1, F2), wherein one of the light sources (30) is arranged in one of the focal points (F1) and the other light source (40) is arranged in the other focal point (F2), wherein the lateral coupling surface (200) of the light coupling region (10) is designed in such a way that, in a region which is at least partially or completely above a first horizontal plane (E1) in which the first light source (30) is arranged, in the vertical direction (R), the lateral boundary surface (200) has a first, curved lateral boundary surface portion (201), and in a region which in the vertical direction (R) lies at least partially or completely below a second horizontal plane (E2) in which the second light source (40) is arranged, the lateral boundary surface (200) has a second, curved lateral boundary surface portion (202), wherein the horizontal planes (E1, E2) are planes which run parallel to a plane (X, Y) to which the vertical axis (Z) is orthogonal and which contains the optical axis (X), and wherein the two lateral boundary surface portions (201, 202) are connected to one another via lateral boundary surface connecting portions (203, 204); and the central light coupling surface (10) is designed as follows: starting from each lateral boundary surface connecting portion (203, 204), a central coupling surface (103, 104) extends in the direction of the other lateral boundary surface connecting portion (204, 203), wherein the central coupling surfaces (103, 104) converge and terminate at a single central edge (110); above and below the central coupling surfaces (103, 104) extend two connection coupling surfaces (101, 102) which connect the central coupling surfaces (103, 104) to the lateral boundary surface portions (201, 202), wherein the central coupling surfaces (103, 104) are concavely curved in horizontal sectional planes—sectional planes which run parallel to a plane (X, Y) to which the vertical axis (Z) is orthogonal, and which contains the optical axis (X) —such that concave central coupling surface contours (103″, 104″) are produced.