Screen distance, eyes, and what the device can measure

iOS 17 added a feature called Screen Distance under Screen Time [source: apple-screen-distance]. It uses the TrueDepth camera. It detects when a child holds an iPhone or iPad closer than 12 inches (about 30 cm) for an extended period. It then prompts the child to move the device further away [source: apple-screen-distance].

Apple describes the feature with a health claim. It says holding the screen too close can contribute to eye strain.

It also says it can contribute to myopia risk in children.

This page is about three things.

First, what the feature actually does and on which devices it is available. The description uses Apple’s own support page as the source.

Second, the eye-strain and myopia benefit language is Apple’s claim. It is not an independent clinical finding in the sources this wiki cites.

Manufacturer claims are kept as [claim]. They are not used as evidence for any health assertion.

Third, what the independent paediatric and ophthalmology literature says. That covers the AAP, the AAO, the WHO under-5 guideline, and the German AWMF/DGKJ guideline.

They cover screens, distance, eye strain, blue light and myopia in children.

The aim is to separate what the device can measure, what the device maker claims that measurement buys, and what the professional eye-care bodies say.

This page is not medical advice. A child with blurry vision, persistent eye-rubbing, frequent headaches or squinting needs an eye examination.

That examination belongs with a paediatric ophthalmologist or optometrist, not a setting on an iPhone [source: www-healthychildren-eyes-screen-time-break].

Definition

A research-grounded separation of three things that the headlines about “screens and eyes” tend to mix up:

• what the iOS Screen Distance feature actually measures and on which devices it runs;
• what the manufacturer of that feature claims the measurement buys, set apart as [claim] and not used as evidence;
• what the independent paediatric and ophthalmology professional bodies (AAP, AAO, WHO, German AWMF/DGKJ) say about screen distance, eye strain, blue light and childhood myopia.

Scope

The page covers iPhone and iPad, iOS 17 and later, on TrueDepth-camera devices [source: apple-screen-distance]. It does not cover the Android ecosystem, game consoles, televisions or e-readers — those either lack an equivalent feature or have a different one.

It covers the eye side of the screens-and-children question. It does not cover the sleep side, which is on Screens and sleep: what is actually established.

It does not cover what to do tonight if a child has new eye symptoms. A child with persistent squinting, eye-rubbing, headaches around the eyes, or blurred distance vision needs a vision screening and, where indicated, a paediatric ophthalmologist or optometrist.

What Screen Distance actually does

Apple’s current support page describes Screen Distance as follows. It is available on iOS 17 and later on devices with a TrueDepth camera [source: apple-screen-distance].

It uses that camera to prompt the user when the device is held closer than 12 inches for an extended period.

For a child under 13 in a Family Sharing group, it is on by default.

It is re-enabled on every child device whenever the child updates a signed-in device [source: apple-screen-distance].

That is the full description of what the feature measures and when it fires.

The Apple page also includes the eye-strain and myopia benefit language. This wiki treats that language separately because the same source is also the device manufacturer [claim: apple-screen-distance].

The German-language Apple page uses Bildschirmabstand for the body of the feature.

It uses Bildschirmentfernung in the screenshot alt text. Both refer to the same iOS feature [source: apple-screen-distance-de].

What the feature does not do is also worth saying out loud:

• It does not measure screen time, app use, or content.
• It does not lock the device or block apps when triggered; it shows a prompt and lets the user move the device.
• It does not differentiate between a 5-year-old’s face and a 16-year-old’s face. The under-13 default and the 12-inch threshold are the only age or distance customisations available through Apple’s current settings [source: apple-screen-distance].
• It requires a TrueDepth camera. iPhones earlier than the X family, all iPads older than the 2018 Pro line, and any device running iOS 16 or earlier do not have it [source: apple-screen-distance].

What Apple says the feature does for eye health

The Apple support page frames the feature as protective against eye strain and as a myopia-prevention measure for children.

This language is presented as [claim] in this wiki.

The reason: Apple is the manufacturer of the device being measured. The same source cannot be both the description of the feature and the independent evidence for the health benefit of the feature [claim: apple-screen-distance].

The user-visible reading of the Apple page, in plain language, is: hold the phone further away and you reduce the risk of eye strain and of myopia in a child.

That statement is plausible. It is also not the kind of statement that can be made about a child’s long-term eye health on the strength of a single device-manufacturer support page.

The two questions worth separating are:

1. Does holding a phone closer than 12 inches really cause eye strain or visual discomfort that moving it further away would relieve?
2. Does moving the phone further away reduce a child’s long-term risk of becoming myopic?

The two are different evidence questions. They have different evidence bases. The first is about short-term symptoms. The second is about a developmental change in the eye over years.

Conflating them is the most common mistake parents make with this feature.

What the independent ophthalmology sources say

The American Academy of Ophthalmology publishes patient-education pages that directly address both questions.

On screen distance and short-term discomfort.

The AAO patient page on computers and digital eye strain was reviewed in June 2024. It recommends sitting about 25 inches (about arm’s length) from a desktop or laptop screen. It recommends positioning it so the eye gazes slightly downward [source: www-aao-computer-eye-strain].

For phones, the AAP HealthyChildren page on screen-time breaks cites an optometric convention. The convention is called the “1/2/10 rule”.

Mobile phones are ideally at one foot. Desktop devices and laptops at two feet. Roughly 10 feet for TV screens, depending on screen size [source: www-healthychildren-eyes-screen-time-break].

The 12-inch Apple threshold is in the same general neighbourhood as the AAP-cited one-foot rule for phones.

On the cause of digital eye strain. The AAO’s computers-and-eye-strain page is explicit.

Quote: “you may have heard that looking at a computer, smartphone, or other digital screen for long periods of time will permanently damage your eyes. Thankfully, this is not true. Neither are the old adagess about ‘ruining your eyes’ from watching too much television or sitting too close to the TV.”

Short-term digital eye strain is real. It is “no different from the symptoms you may have when reading, writing, or doing ‘close work’ like sewing for long stretches of time” [source: www-aao-computer-eye-strain].

The AAO attributes the short-term symptoms to reduced blink rate, not to screen distance alone.

Quote: people “normally blink about 15 times in one minute. However, studies show that we only blink about 5 to 7 times in a minute while using computers and other digital screen devices”.

Looking up and away, blinking more often, and using artificial tears for dryness are the recommended fixes [source: www-aao-computer-eye-strain].

On blue light.

The AAO Digital Devices page was reviewed in December 2025. It is direct.

The blue light from computer screens has not been shown to harm human eyes. It has not been shown to contribute to age-related macular degeneration. Blue-light-blocking glasses are not necessary.

Quote: “Blue light from computers will not lead to eye disease. [Over]exposure to blue light and UV light rays from the sun can raise the risk of eye disease, but the small amount of blue light coming from computer screens has never been shown to harm your eyes” [source: www-aao-digital-devices-and-eyes].

The AAP HealthyChildren page on screen-time breaks says the same thing differently. Quote: “Although there is no evidence that blue-light is harmful to the eyes, it can make it harder for children to fall asleep and contribute to eye strain”.

The same page notes that turning screens off an hour before bedtime and the 20/20/20 rule are the real fix [source: www-healthychildren-eyes-screen-time-break].

On myopia.

The AAP HealthyChildren page on myopia in children and adolescents was last updated in September 2023. It notes that myopia “is on the rise overall, especially in kids”.

Quote: “No one is exactly sure why, but experts believe it could be related to more time doing closeup tasks indoors like using computers and playing video games” [source: www-healthychildren-myopia-children-teens].

That wording is careful.

The AAP does not say screen distance has been shown to cause or prevent myopia.

It says close-up indoor activity and time-on-screens may be part of the explanation. It also says “more time playing outside may result in healthier vision development in children” [source: www-healthychildren-eyes-screen-time-break] [source: www-healthychildren-myopia-children-teens].

The AAP’s own treatment options for slowing myopia progression in childhood include low-dose atropine eye drops. They also include specialised multifocal contact lenses and orthokeratology.

They do not include device-based distance enforcement [source: www-healthychildren-myopia-children-teens].

The German AWMF/DGKJ S2k guideline treats screens as one of several risk factors in dysregulated media use. Its age-by-age minute schedule recommends against screens below age 3. It sets limits at older ages.

It does not name a specific screen-distance intervention [source: register-awmf-dgkj-2023].

The WHO under-5 guideline similarly does not include a screen-distance recommendation. Its recommendations are about total sedentary screen time and the developmental content of what is watched [source: who-under5-2019].

What follows from this for a parent

Three practical conclusions follow.

The Apple Screen Distance prompt is consistent with the independent optometric guidance.

The 1-foot AAP-cited phone-distance rule and the AAO’s 25-inch desktop rule are in the same range as Apple’s 12-inch prompt.

A child who receives and acts on the prompt is doing what the eye-care bodies recommend. The feature is consistent with the guidance. It is not a replacement for it.

The feature is not the place to look for a long-term myopia fix.

The independent evidence on myopia progression in childhood supports time outdoors. It also supports ophthalmologist-supervised treatments in selected cases.

There is no evidence that a screen-distance prompt by itself changes a child’s long-term refractive outcome.

The AAP’s myopia page does not list screen-distance software as a treatment. It lists atropine, specialised contact lenses, orthokeratology and outdoor time [source: www-healthychildren-myopia-children-teens].

If a child has eye symptoms, the device feature is not the diagnosis.

Persistent squinting, eye-rubbing, headaches around the eyes or temple, blurred distance vision, or complaint of not being able to see the board at school are reasons for a vision screening at the paediatrician’s office.

If needed, that is a referral to a paediatric ophthalmologist or optometrist.

The AAP and the American Academy of Ophthalmology jointly recommend eye checks at well-child visits starting at birth.

Vision screenings begin at age 3. Instrument-based screening is possible from age 1 to 2 [source: www-healthychildren-eyes-screen-time-break].

The Screen Distance prompt does not see any of that. It measures a distance and suggests a movement.

What is well established

Digital eye strain is real.

Reduced blink rate on screens causes dryness, blurring and headaches. The symptom is temporary. It is relieved by blinking more, looking up and away, and using artificial tears [source: www-aao-computer-eye-strain].

Holding screens at a reasonable distance is consistent with what eye-care bodies recommend. A phone at one foot, a desktop or laptop at two feet, a TV at ten feet — these are the conventions cited by the AAP and AAO.

The AAP cites them on the screen-time-breaks page. The AAO cites them on the computers-and-eye-strain page [source: www-healthychildren-eyes-screen-time-break] [source: www-aao-computer-eye-strain].

Myopia is rising in children and the cause is not settled.

The AAP explicitly says “no one is exactly sure why”. It lists candidate explanations including close-up indoor activity [source: www-healthychildren-myopia-children-teens].

Outdoor time is plausibly protective against myopia progression.

The AAP cites evidence that “more time playing outside may result in healthier vision development”.

It also says spending time outdoors “can also help with myopia management” [source: www-healthychildren-eyes-screen-time-break] [source: www-healthychildren-myopia-children-teens].

Blue light from screens has not been shown to harm human eyes or to cause macular degeneration.

Both the AAO and the AAP say this [source: www-aao-digital-devices-and-eyes] [source: www-healthychildren-eyes-screen-time-break].

What is plausible but not proven

That a screen-distance intervention by itself would shift a child’s refractive outcome.

The AAP’s treatment options for myopia in childhood do not include a device-side distance enforcement.

Whether the cumulative effect of years of holding a phone at a slightly greater distance makes a measurable long- term difference is not established in the cited sources.

That AAP-cited “1/2/10” distances are evidence-graded optometric guidelines.

The 20/20/20 rule and the 1/2/10 rule appear on the AAP patient-education page. They come from the American Optometric Association.

They are clinician consensus on the AAP page, not the result of randomised trials of distance interventions [source: www-healthychildren-eyes-screen-time-break].

That reduced blink rate, not screen distance, is the primary driver of short-term digital eye strain.

This is the AAO’s framing. It is consistent with what is known about ocular surface physiology.

It is not the result of head-to-head trials of “blink more” versus “hold further away”. The literature on blink rate and screen use is largely observational [source: www-aao-computer-eye-strain].

What is claimed and is not supported

That special “blue light blocking” glasses protect children’s eyes or improve their sleep.

Both the AAP HealthyChildren page and the AAO Digital Devices page are explicit that the purchase is unnecessary [source: www-aao-digital-devices-and-eyes] [source: www-healthychildren-eyes-screen-time-break].

That screens permanently damage children’s eyes.

The AAO’s computers-and-eye-strain page calls this out directly. It quotes the worry, then states it is not true.

The exact quote: “you may have heard that looking at a computer, smartphone, or other digital screen for long periods of time will permanently damage your eyes. Thankfully, this is not true” [source: www-aao-computer-eye-strain].

The AAP’s eyes-and-screen-time page on the same point is broader. It says “there is no evidence that screen use harms children’s eyes or their developing visual systems” [source: www-aao-digital-devices-and-eyes].

That sitting too close to a TV “ruins your eyes”.

Same AAO source. This is a folklore claim. The AAO addresses it and rejects it [source: www-aao-computer-eye-strain].

What we do not know

Whether moving a phone from 8 inches to 14 inches for hours a day, cumulatively over years, makes a measurable difference to a child’s refractive error.

The cited sources treat distance as a good habit.

They treat outdoor time as the established protective factor.

They do not have a controlled comparison of distance-by-distance refractive outcomes.

Whether the iOS Screen Distance prompt changes child behaviour in a way that lasts.

Apple’s documentation describes the prompt.

It does not publish data on whether children who receive it hold the device further away over weeks or months.

The 12-inch threshold is a setting. The evidence for its behavioural or refractive effect is not in the sources this wiki cites.

What the right distance is for a tablet held in bed at night, at an angle the TrueDepth camera cannot read reliably.

Apple does not address reading posture in its support page. Independent guidance on the 1/2/10 rule treats tablets somewhere between phones and laptops.

No source this wiki cites gives a single number for that case [source: www-healthychildren-eyes-screen-time-break].

What share of the rise in childhood myopia is attributable to screens versus genetics versus outdoor time versus education-related near work.

The AAP and the underlying myopia literature both treat this as multifactorial and not fully quantified [source: www-healthychildren-myopia-children-teens].

How to use the Screen Distance feature honestly

The feature is reasonable to leave on. It is on by default for under-13 children in a Family Sharing group. A child who acts on the prompt is doing what the eye-care bodies recommend anyway [source: apple-screen-distance].

It is not reasonable to treat the feature as proof that the device is taking care of a child’s eye health. The feature measures distance.

It does not measure outdoor time, blink rate, screen time, sleep, refractive error or any of the things the eye-care bodies treat as the real variables.

A parent who wants a screen-distance feature with independent evidence behind it does not need one. The AAP-cited 1/2/10 rule is the same convention.

It is stated in plain language, on a non-commercial professional page [source: www-healthychildren-eyes-screen-time-break].

A parent whose child has eye symptoms needs a vision screening. Where indicated, it needs a paediatric ophthalmologist. Neither is a settings change.

A parent who wants to lower long-term myopia risk should follow the AAP’s outdoor-time guidance more than any device feature [source: www-healthychildren-myopia-children-teens].

The honest version of this page is short: the feature is fine. The eye-strain benefit is plausible.

The myopia-protection claim is Apple’s [claim], not the paediatric consensus.

The AAP and AAO do not endorse blue-light glasses as either an eye or a sleep fix.

Sources

This page draws on the following sources. Manufacturer claims are kept as [claim]. They are not used as evidence for any health statement.

Every other cited source is a professional body, a public-health agency, or a peer-reviewed paper.

Professional and guideline sources:

• apple-screen-distance — Apple Support page describing the Screen Distance feature (iOS 17+ on TrueDepth-camera devices). Its eye-strain and myopia benefit language is treated as Apple [claim], not as independent clinical evidence.
• apple-screen-distance-de — German-language Apple Support page (Bildschirmabstand / Bildschirmentfernung).
• apple-screen-time — Apple Support page on Screen Time generally.
• publications-aap-digital-ecosystems-2026 — AAP 2026 technical report on digital ecosystems, children and adolescents.
• www-healthychildren-eyes-screen-time-break — AAP HealthyChildren.org page on screen-time breaks and children’s eye health; 20/20/20 rule, 1/2/10 rule, blue-light-filtering glasses, sleep, vision screening.
• www-healthychildren-myopia-children-teens — AAP HealthyChildren.org page on myopia epidemiology, suspected environmental drivers, and outdoor time as a possible protective factor.
• www-aao-computer-eye-strain — AAO patient-education page on computer and digital-device eye strain, viewing distance, blink rate and ergonomics.
• www-aao-digital-devices-and-eyes — AAO patient-education page on blue light, digital eye strain, sleep, blue-light glasses and screen-time for kids.
• who-under5-2019 — WHO 2019 guidelines on physical activity, sedentary behaviour and sleep for children under 5.
• register-awmf-dgkj-2023 — German AWMF/DGKJ S2k guideline on prevention of dysregulated screen media use.