Tech titans from Apple and Google to Instagram and Twitter are touting “dark mode” as the latest digital must-have.

But what exactly IS dark mode - and is it worth ticking the settings box to get it? 

Dark mode is simply a visual option that reverses the colours of text and background on a screen, cutting down the glare when you use an operating system, platform or app. Instead of black text on a white background, dark mode uses shades of grey. 

This reduces the visual contrast on our screens and, according to the hype, will not only improve the battery life of your device, but reduce eye-strain, sleep difficulties and headaches.

Here’s how Apple describes in its latest release:

"Dark Mode is a dramatic new look that helps you focus on your work. The subtle colors and fine points of your content take center screen as toolbars and menus recede into the background. Switch it on in the General pane in System Preferences to create a beautiful, distraction-free working environment that’s easy on the eyes—in every way."

So should I switch?

Maybe - but first consider that critics have cast serious doubt on these claims.

According to specialist Andrew Couts, writing in Gizmodo, dark mode is “the placebo of tech.” Expert opinion increasingly agrees. 

“Except in extraordinary situations, dark mode is not easy on the eyes, in any way,” insists tech journalist Adam Engst - and the claims for it simply “fly in the face of the science of human visual perception.”

The science shows conclusively that the human brain and eye prefer dark-on-light contrast - which is associated with better focusing, comprehension and reading speed. 

Research also shows that for people with astigmatism - aka short-sightedness - dark mode can be especially counter-productive and actually aggravate the condition.

What about battery life?

Depending on your device, it may be true that dark mode will extend battery life for up to an hour a day. But for many devices - specifically non-OLED ones - it will not affect battery life at all.

What about sleep?

Most of us are now aware that the blue light emitted from screens can wreak havoc on healthy sleep patterns. The good news is that dark mode does reduce blue light and may be a good choice for evening viewing or scrolling.

The good news is that dark mode does reduce blue light and may be a good choice for evening viewing or scrolling.

Experts advise that dark mode can certainly reduce visual fatigue, especially at night, when a phone or laptop screen that seemed perfectly fine during the day may feel uncomfortably bright.