How to keep your night vision when you're using a phone to stargaze

The faint stuff in the sky only shows up once your eyes are adapted to the dark. That takes 20 to 30 minutes. A bright phone screen in the middle of it sets you back several minutes each time.

Astronomers use red torches for this reason. You can make an iPhone do something similar.

Turn the whole screen red (iOS)

1. Open Settings › Accessibility › Display & Text Size › Color Filters.
2. Turn on Color Filters and choose Color Tint.
3. Set Hue all the way to red and Intensity to the maximum.
4. Go to Settings › Accessibility › Accessibility Shortcut and pick Color Filters. Now a triple-click on the side button switches red on and off.

This works for every app, Sky Map included. Turn brightness right down too.

Other habits that help

• Look at the phone with one eye only, and keep the other closed. The closed eye stays adapted.
• Keep phone checks short: confirm, put it away, look up.
• Use averted vision for faint objects: look slightly to the side, and the object appears.
• Don’t look at car headlights or street lights while you wait.

Plan before you lose your night vision

Check the planet timeline and the sky conditions in Sky Map indoors. Then you only need the phone outside for short checks.

Impressive star map

I love how the app adapts to my location with weather conditions and visibility info. Very cool knowing which planets are out. The app is also very well designed with nice animations.

★★★★★ App Store review, United States, 4 April 2026, Finallyreadyfortheexam · App Store

Related: stargazing with kids.