Tattoos may cause Apple Watch to stop working

You may want to think twice if you were saving your pennies for an Apple watch and sport arm tattoos.

Apple watches are malfunctioning when worn on tattooed wrists.

Users have experienced the watch locking up, not sending notifications, and losing the ability to use some apps, Apple Pay or place phone calls when worn over inked skin.

The issue, which was confirmed by Apple blog iMore, stems from the watch's heart rate reading technology.

Apple explains that the back of the watch flashes green and infrared lights, which is either absorbed or reflected by blood and allows the watch to sense a heartbeat.

But tattoo ink is opaque, meaning no outside light will penetrate through tatted skin.

Solid-colored tattoos, especially red ones, reflect back only red light and solid-black tattoos absorb both colors of lights, causing the heartbeat detection to malfunction.

Though the wrist detection can be shut off, the Apple Watch requires the detection technology to be on to use a plethora of its applications.

It is noted that the watch does work fine on dark-colored skin, and over scars and skin abrasions.

In these cases, the skin is translucent and allows the lights to pass through.