Nov. 29, 2018—Just over half of 2018 model vehicles IIHS recently evaluated are available with headlights that do an adequate job of lighting the road at night and limiting glare for oncoming drivers. However, most good-rated headlights are optional or bundled with features that can raise the price of a vehicle.
Since the Institute released its first headlight ratings for passenger vehicles in 2016, manufacturers have focused on improving this safety feature. In 2016, only 2 of 95 headlight systems that IIHS evaluated earned a good rating.
For the 2018 model year, the best-available headlights on 32 of 165 models evaluated earn the highest rating of good, and the best-available headlights on 58 models earn the second-highest rating of acceptable. Thirty-two models have only marginal-rated headlights, while poor-rated headlights are the only ones available for 43 models.
Most headlights use one of three light sources: halogen, high-intensity discharge (HID) or LED. Each of these can be paired with either a multifaceted reflector or a projector lens. Projector headlights use one lens to spread the light out, while reflectors use shiny surfaces that bounce the light forward.
Visit here to read more and see a visual of poor versus good headlights.