How to Set Up Screen Distance on Your iPhone
A simple iPhone setting that can encourage healthier viewing habits
If you or your child tends to hold a phone very close to the face, Apple's Screen Distance feature can remind you to move it farther away.
It uses the iPhone's TrueDepth camera to detect prolonged viewing at a distance of approximately 30 cm (12 inches) or closer and displays an alert encouraging you to increase the distance
How to turn it on
Open Settings
Tap Screen Time
Tap Screen Distance
Turn Screen Distance on
For a child using Family Sharing, you can access the child's Screen Distance setting through their Screen Time settings.
Dr Lee's Perspective
Children’s eye problems and phone use
I like this feature because it turns an abstract instruction—"Don't hold your phone so close"—into something your child can actually see and respond to.
But I wouldn't rely on distance alone.
My bigger concern is prolonged near work without a proper break A child can hold a phone at a perfectly reasonable distance and still spend hours looking at it.
So my advice is:
Distance on phone + breaks every 20 minutes+ 1 hour outdoor time.
Do read more on myopia control in kids which is a true concern of mine.