# Dark adaptation

Also called: night vision, red light.

Your eyes becoming far more sensitive in the dark — it takes 20–30 minutes and one white light ruins it.

In darkness your pupils open to 5–7 mm within seconds, but the real gain is chemical: the rods in your retina rebuild a light-sensitive pigment over 20–30 minutes, making you thousands of times more sensitive to faint light. A glance at a bright phone or torch resets much of it.

Red light disturbs the rods least, which is why observers use dim red torches.

**At the eyepiece:** Turn your phone to its night/red mode, cover bright screens, and give yourself half an hour before hunting faint objects.

**In AstroPilot:** The eye button at the top switches AstroPilot to red night-vision mode.

**Related:** [Averted vision](https://astropilot.space/glossary/averted-vision.md), [Exit pupil](https://astropilot.space/glossary/exit-pupil.md), [Limiting magnitude](https://astropilot.space/glossary/limiting-magnitude.md)

From the AstroPilot astronomy glossary: https://astropilot.space/glossary/dark-adaptation