Why Red Light on Head Torch?

The red light on a headlamp is intended for preserving your night vision while still providing some light so you can see. Additionally red light modes on a headlamp aren't as blinding to your friends, so it is ideal when using a headlamp with a group of people. Cool! Headlamps preserve your night vision.

Why do you use a red light at night?

It takes a very low light level sensed by the eyes to produce this chemical called rhodopsin, or visual purple. ... It is an interesting trait that deep red lights do not trigger the neutralization of the rhodopsin, so astronomers and safety officials use red lights for night lighting to allow night vision to continue.

Why do headlamps have red and green lights?

Red light is the universal signal for attention, so it is a great thing to have in emergencies for signaling and safety. Green LEDs are useful for night vision.