The present invention relates to an optical element (2) for collimating light from a light source (3), said optical element (2) having an in-coupling side (5) arranged to receive said light, an out-coupling side (6) arranged to allow for emission of collimated light, and an element body extending from said in-coupling side (5) to said out-coupling side (6), the element body having a cross-section perpendicular to an optical axis (z) defined by an x-5 axis and a y-axis being perpendicular to each other, wherein said optical element (2) has an x-curvature along said x-axis and a y-curvature along said y-axis, said y-curvature being greater than said x-curvature, thereby enabling for a light distribution of said collimated light emitted from said out-coupling side (6) to have a cross-section of an asymmetric shape (CE) perpendicular to said optical axis (z). The present invention also relates to a lighting system (1) comprising such an optical element (2). An advantage with the present invention is that it may provide asymmetric light distribution with an increased beam-width difference in two perpendicular viewing directions.
