This article presents a new eyelid localization algorithm based on a parabolic curve fitting. To deal with eyelashes, low contrast or false detection due to iris texture, we propose a two steps algorithm. First, possible edge candidates are selected by applying an edge detection on a restricted area inside the iris. Then, a gradient maximisation is applied along every parabola, on a larger area, to refine the parameters and select the best one. Experiments have been conducted on the CASIA-IrisV3-Interval database that have been manually segmented. A new performance measure is proposed, carried out by comparing the segmented images obtained by the proposed method with the manual segmentation.