Sky Ember

Your screen, timed to your sky.

A bright screen after dark cuts melatonin by half and pushes your body clock later. Sky Ember warms your Mac's display the way the sky warms at dusk, gliding from daylight neutral to candlelight as the sun sets over your horizon. And when true darkness matters, one click takes you where no built-in setting can: pure red.

Protects melatonin

In rhythm with your body clock

Grounded in peer-reviewed research

$9.99 · one-time · macOS 13+ · Apple Silicon & Intel

Follow the sun

One on-device location fix. Your screen tracks the sun's real arc: neutral only at midday, gold by late afternoon, candlelight at dusk. Nothing to schedule.

True red mode

Green and blue removed entirely. Not tinted, gone. The wavelength that spares night vision and melatonin. Night Shift can't do this.

Flicker-free dimming

Dim below the backlight's minimum without PWM flicker. The image darkens, the light never pulses. Made for dark rooms and sensitive eyes.

Private by architecture

No accounts, no analytics, no network code at all. Sky Ember cannot phone home. Your location never leaves your Mac.

What the science actually says

Your eyes do more than see. A small set of cells in the retina, most sensitive to blue light near 480 nm, has one job: telling your brain's master clock that the sun is up. Screens emit strongly in exactly that band, so a bright screen after dark keeps reporting daytime long after the sky has moved on.

55%

How much less melatonin Harvard researchers measured after people read on a bright, blue-rich screen before bed instead of a printed book.

1.5 hrs

How far the same study found five evenings of bedtime screen reading pushed the body clock later. Readers were also groggier the next morning.

3 hrs

How long before bed a 2022 consensus of circadian scientists recommends keeping your light warm and dim. Sky Ember starts that glide at your local sunset, automatically.

And to be fair to blue light: at screen brightness it does not damage your eyes. The American Academy of Ophthalmology is clear on that, and blue-rich light during the day is genuinely good for you. The measured problem is timing. Sky Ember reduces your exposure only when it matters: neutral while the sun is high, candlelight after dark, and a red mode your body clock barely registers at all.

Sources: Chang et al., PNAS 2015 · Brown et al., PLOS Biology 2022 · American Academy of Ophthalmology

The astronomer's secret, one click away

Astronomers, pilots, and stargazers have used red light for a century. It is the wavelength your night vision ignores. Sky Ember's Red mode turns your whole screen into that lamp: reading beside a sleeping partner, checking something at 2 AM, winding down before bed.

Sky Ember red mode: the panel rendered in pure red

Free wallpaper

The afterglow, for your desktop

The quarter hour after sunset, mapped: the sky's gradient from indigo to ember, the sun's arc plotted in small dimming points. Made for the 16″ MacBook Pro at full 3456 × 2234, and it scales beautifully to any display.

Sky Ember wallpaper: a twilight gradient from deep indigo through violet to ember, with the sun's arc traced in faint dimming points

Download the wallpaper

PNG · 3456 × 2234 · 5 MB · free, no email needed

And for after dark: the same sky through Sky Ember's red mode.

The same wallpaper in red mode: black gliding down into deep ember red, the sun's arc traced in faint red points

Download the red version

PNG · 3456 × 2234 · 2.7 MB · free