Apple’s iPhone and iPad interfaces are attractive, but they can also be difficult for some people to see – especially interface elements like switches, which change color when activated. Fortunately, there is a way to add “1
First, open Settings on your iPhone or iPad.
In Settings, tap Accessibility.
In Accessibility, select ‘Display and text size’.
In “Display & Text Size”, tap the switch next to “Power Labels” to turn it on.
You will notice that once you enable this feature, all switches on the screen have stylized “1” (a clear vertical line) and “0” (a circle) labels, where “1” means “on” and ‘0’ means’ from’. These comply with international standards for on / off switch labels.
This change applies to Apple’s Settings app and any other app that uses the default system power switch design, including third-party apps such as Twitter.
If you need an extra visual boost to make the switches even more visible, tap the Increase Contrast switch on the same page (in Accessibility> Display & Text Size). When done, leave the Settings app. The changes are active.