(MEDIA GENERAL) – The Apple Watch hit the market last week. And as thousands of technophiles flocked to buy the savvy tech giant’s latest product, a select niche is walking away unimpressed: people with tattoos.
Apple Watch wearers first voiced complaints on Twitter and Reddit, and Apple blog iMore confirmed the Apple Watch doesn’t function properly when worn atop a tattoo.
As a safety precaution, the Apple Watch uses your heart rate to determine when the watch is being worn and will disable certain actions if not being worn – including receiving notifications, placing calls and certain apps.
A support article posted by Apple explains the issue.
“Apple Watch uses green LED lights paired with light-sensitive photodiodes to detect the amount of blood flowing through your wrist at any given moment. When your heart beats, the blood flow in your wrist – and the green light absorption – is greater. Between beats, it’s less,” Apple said. “By flashing its LED lights hundreds of times per second, Apple Watch can calculate the number of times the heart beats each minute – your heart rate.”
Solid-colored tattoos, particularly red and black tattoos, absorb the green light and reflect back red light, disabling the heart rate monitor.
Currently, users can turn off wrist detection to receive notifications, but the Apple Watch will not receive calls or enable Apple Pay with the wrist detection disabled.