In the process of headlight adjustment, it is crucial to differentiate between the left and right headlights. Typically, the left headlight is adjusted to the right, and the right headlight is adjusted to the left. This ensures that the beams of light are directed correctly onto the road, enhancing visibility and safety. According to a study by the National Highway Traffic Safety Administration (NHTSA), improper headlight alignment can lead to a significant reduction in road visibility, increasing the risk of accidents by up to 25%. The adjustment process is based on the principle of aiming the light to the right of the centerline for the left headlight and to the left of the centerline for the right headlight, ensuring that the beams do not shine into oncoming traffic.