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"As a group, midsize SUV headlights perform slightly better than the other SUVs and pickups we evaluated last year, and that's encouraging," IIHS senior research engineer Matt Brumbelow said in a statement. "Still, we continue to see headlights that compromise safety because they only provide a short view down the road at night."

The two categories, luxury and non-luxury, each had one model given a good rating for their best available headlight system. The 2017 Volvo XC60 from the luxury side and the 2017 Hyundai Santa Fe from the non-luxury side.

According to IIHS, most headlights in vehicles have one of three different light sources, which include halogen, high-intensity discharge (HID) or LED. One of these sources is then paired with either reflectors or projector lenses. Projector headlights use one lens to spread light while reflectors have multiple surfaces that bounce light forward.

Each of the good and acceptable-rated headlights in the test done by IIHS have projector lenses, and the good-rated vehicles also have HID light sources.

The XC60 has curve-adaptive HID projector headlights available, which earned it the top rating. The XC60 is also available with optional high-beam assist that automatically switches the lights from high to low beam. The good-rated HID headlights are available if XC60 purchasers upgrade to the "advanced package" or the "active dual xenon headlights package."

The Santa Fe has curve-adaptive HID projector headlights with high-beam assist like the XC60. The good-rated headlights are available in the "tech package" which can be added on to the two "ultimate" versions of the Santa Fe, the "SE Ultimate" and "Limited Ultimate" but not the two more basic versions, the "SE" and the "Limited," according to its website.

According to IIHS, the Santa Fe's base halogen headlights earn a poor rating due to inadequate visibility.

There are 79 different headlight combinations available for the 37 midsize SUV models that IIHS tested. The best available lights indicated the ratings for the model.

Engineers at IIHS measure how far light is projected from the low beams as well as high beams as the vehicle drives straight and around curves. Glare for oncoming vehicles is another factor to make sure that low beams aren't creating excessive glare.

The Kia Sorento was one of the worst tested by IIHS in terms of visibility on straightaways and gradual curves. The Ford Edge was another model that received a poor rating for its lack of visibility.

While the Hyundai Santa Fe had a headlight combination that performed in the top category, the Santa Fe Sport has three different headlight combinations and all three-rate poor because they create excessive glare.

"Managing glare can be more challenging for taller vehicles like SUVs and pickups because their headlights are mounted higher than on cars," Brumbelow said. "Better aim at the factory can minimize glare."

Despite the glare problems and poor headlight ratings, the 2017 Sorento and 2017 Santa Fe Sport both were regarded as an IIHS Top Safety Pick because of their optional front crash prevention.

IIHS said 17 of the 79 headlight variants would be rated as poor due to excessive glare alone and glare complaints are common.

The National Highway Traffic Safety Administration shows there are 136 glare-related complaints submitted on 2013-2017 vehicle models, with just seven of those coming from 2017 models so far. No complaints have been filed to the NHTSA for the 37 midsize SUVs tested by IIHS in this report.