This hidden iPhone 17 setting is destroying your eyes

https://www.pocket-lint.com/iphone-17-pwm/

Publish Date: 2026-03-17 07:00:00

Apple is kind of notorious for hiding important features. On iPads, for example, there are options to shrink the size of the interface to fit more text and graphics onscreen, or switch back to the earlier multitasking system if you don’t like Mac-style windows. The company does deliver a few helpful suggestions via its Tips app, but otherwise, you’re left to discover a lot of customization options on your own.

iPhones are no exception. In fact, if using your iPhone 17 or iPhone Air in low light is bothering you, there may be just a single, somewhat cryptic option you need to change, buried a couple of layers down in the iOS Settings app. While I’m at it, if you don’t have a 17 or Air, I’m going to touch on a few general iPhone settings (and habits) that can make things better for sensitive eyes. You might also benefit if you’re having trouble with reading, or like me, getting to sleep on time can be an ordeal.

The ins and outs of pulse smoothing

What you need to know

Devices based on LED lighting don’t necessarily control brightness the way you’d expect. When you imagine a light brightening or dimming, you’re probably picturing an incandescent bulb, which changes strictly based on the amount of power flowing through it.

Certainly, power levels are still important on LED devices, but often what’s going on is something called pulse width modulation, or PWM for…

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