Lane detection is challenging under varied light conditions (e.g., night, shadow, and dazzling light) because a lane becomes blurred and extracting features becomes more difficult. Some researchers have proposed methods based on multitask learning and contextual information to solve this problem; however, these methods result in additional computing. A data enhancement method based on retinex theory is proposed. This method improves the adaptability of a lane model under varied light conditions. In particular, we design an image enhancement network for calculating the reflectivity of images, modifying their exposure, and then generating images with consistent exposure. These images are fed to the lane detection model for training and detection. Our network consists of two parts: exposure-consistent image generation and lane detection. We validate our method on the CULane dataset, and results show that it can improve lane detection performance, particularly on light-related datasets.