Here in the North Country we have about 8 hours of sunlight this time of year so lights are very important. We are also having the heaviest snow fall on record for December add that to quite a few cloudy days and you need your lights pretty much all the time. Checking your headlamps after driving you notice one is out so you replace the bulb which can take from a few minutes to a hour depending on your vehicle, if they are easy to replace I usually replace both at the same time or if they are a chore I may heat the garage and then I would replace them both. Depending upon if I can find them on sale I have been using the Xenon lamps recently have them in one vehicle and so far they are OK. There are other things to check when you replace the bulb. In 1983 headlamp regulations were amended to allow composite headlamps to replace the sealed beamsWith the sealed beam lamp you replaced the bulb lens and reflective surface. Today when you replace the bulb none of these are replaced so they should be checked. If the reflective surface is tarnished or discolored the entire housing must be replaced which can be expensive unless you can find a serviceable used one. A tarnished or discolored reflective surface is usually an indication of a leak so the housing will have to be replaced in time anyway. If the lens is cloudy or scratched there are several alternatives. There are several polishes on the market which I have used and they all do a good job. I was amazed at how they sharpened up the look of a vehicle after I use them on the taillights. If they are badly deteriorated there is a restorative kit and several shops are advertising repair again what I have seen all are a great alternative. The most important item is to check your lights. A manager of a Jiffy Lube told me once if he could get his help to check all the lights he could afford an addition to his house. I know we averaged 1 in 4 vehicles having a bulb out when servicing them. So check your lights and take a glance at the tire at the same time. As my Dad used to say walk around to the passenger side once in awhile and you will save a lot of headaches.