This is possible thanks to something called “active shuttering” technology.

French automotive supplier Valeo has developed “smart” sunglasses called Les Lunettes that aim to remedy a frequent problem for night drivers, Forbes writes. The article says that the sunglasses reduce the brightness of headlights from oncoming cars without dimming the brightness of your own car’s lights. Making use of “active shuttering” technology, Les Lunettes work like regular sunglasses in the day, but can “can be activated before entering a tunnel to prevent glare from blinding the driver when exiting out the other side.”

Read more at Forbes