What are the differences between having a lens and not having a lens?

[LeBrynlee]

There are differences in brightness, lighting effect, and car appearance between having a lens and not having one. A lens can focus the car's light, allowing the light to spread evenly on the road, achieving better illumination. Without a lens, the car's lighting effect tends to be scattered, which can easily affect the vision of other drivers when encountering oncoming vehicles. Lenses come in two types: single-beam and dual-beam. A single-beam lens controls only one bulb, meaning the low beam and high beam are separate, and it can only control the low beam. A dual-beam lens, through an internal shutter, controls both light sources—high beam and low beam—allowing for seamless switching between the two.