u/CrptMoon

Hi,

After digging a bit deeper into smartphone proximity sensors, I came across a warning from Google regarding their Pixel phones which have class 1 lasers

>

This made me wonder: in practical terms, how could a phone’s proximity sensor be damaged in a way that would make it optically unsafe?

Edit:
someone someday might find this useful.

Using a camera recording at 240 fps, I counted the frames where the proximity IR emitter is visibly ON vs OFF on the iPhone SE (2nd generation) by Apple:

• iOS 14.3.1 → ~4 frames ON / ~8 frames OFF → ~20 Hz, ~33% duty cycle
• iOS 26.4.x → ~3 frames ON / ~76 frames OFF → ~3 Hz, ~3.8% duty cycle

It appears Apple quietly reduced how often the proximity emitter pulses by almost 10×, while keeping the pulse length roughly the same.

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Hi,

The proximity sensor IR emitter on my iPhone SE 2 seems to be active whenever the screen is on (not just during calls). I can see it pulsing through another camera.

I’ve attached a video.

Is this normal, and is the IR emission from this sensor considered eye safe for longterm use? I’m mainly concerned about constant exposure since the phone is often close to my face. Is there a way to approximate its output power?

https://reddit.com/link/1syggy8/video/daedrcwnc0yg1/player

Hey all,

I’m trying to figure out if there is any tweak or method to completely disable the proximity sensor. I noticed that it's always on when the screen is on which is kinda dumb

Is there anything currently working on iOS 13.4.1 or is this basically not possible anymore without a kernel-level patch? I don't want to update to 26 and regret it later but that might fix it

Thanks.

I’m trying to determine whether this is normal behavior or a fault.

Using another phone’s camera pointed at the earpiece area, I can observe the proximity sensor’s infrared emitter blinking any time the display is on.

My understanding is that the proximity sensor is mainly used during calls to turn the screen off when the phone is against your face, and otherwise only activated by the OS when needed and not continuously for as long as the screen is lit.

For comparison, on my iPhone 8, the IR emitter is not constantly active while the screen is on.

Could other SE (2nd gen) owners check this?

How to test:

1. Turn the screen on.
2. Use another smartphone camera and point it at the earpiece area.
3. Check whether you notice a small blinking IR light.

On my iPhone SE (2nd generation), the proximity sensor appears active anytime the screen is on, even when I’m not in a call.

I thought it should only activate during calls.

Can someone with the same phone check if theirs does this too?
Trying to figure out if this is normal or a defect.