When it comes to headlamps, they've gone through quite the evolution thanks to high-powered, bright, efficient, and small LEDs. One company that's leading the way is with rugged lighting products is Fenix.
Fenix is pronounced “phoenix” and is a high-end lighting brand that sells products ranging from flashlights, headlamps, bike lights, and lanterns. Their calling card are their ability to withstand harsh environments, durability, and ridiculously bright LEDs.
This is measured by lumens which is defined as “a unit of luminous flux in the International System of Units, that is equal to the amount of light given out through a solid angle by a source of one candela intensity radiating equally in all directions.”
This thing is flat out the most comfortable headlamp I've ever owned. A big part of it their headband and top band that goes away from the traditional cotton-like elastic bands that Black Diamond and Petzl uses and instead leverages a vented elastic material that helps with sweat.