Another important factor car headlights must be properly aligned in a manner that will not blind other motorists on the road while at the same ensuring maximum visibility on the road. It is recommended that the proper aim should be checked after one year or any time the replacement of one or more headlight is done or there is a front-end body work done on the car. The adjustment procedure offers only a relative correction, and the person must wait until a specialist intervenes and uses the appropriate method. Early body style headlights feature an adjusting screw on top for up-and-down movement and one on the side for left-and-right movement, while late models have two screws: one for left-and-right attached to one of the sides of the garment and the other, for up-and-down located at the bottom of the garment. To align the headlights the following are needed, a blank wall at a distance of 25 feet in front of the vehicle and a level floor. When preparing and marking the wall, vertical masking tape should be positioned along the line of the car's centerline, as well as, centerline of the headlights; additionally, there has to be a horizontal tape line. It should be stationary, with some fuel in its tank although not full, and not carrying any bulky items. For low beam adjustment the HIGH INTENSITY ZONE should be set two inches below the nominal horizontal line and two inches right of the vertical lighter line adjustment screws. When high beams are on, the high intensity area should be slightly below the line horizontally though low beams are more important and commonly used for safety. It is recommended that one should see an expert to have the headlights realigned as soon as possible.