That’s according to a new thread on Reddit which claims that several tattoo-sporting Apple Watch customers are having trouble using the device, because the wearable’s wrist-detection feature gets confused by the way in which tattoos reflect the green and infrared light emitted by the Watch.
This results in users with tattoos not receiving their notifications on their wrist, unless they move it to an un-tattooed area, or turn off wrist detections. Not an option for those with full sleeves.
Redditor guinne55fan thought that his shiny new 42mm Apple Watch Sport had a bad wrist detector sensor, as the Watch would lockup whenever the screen went dark, and it then asked for a password. No notifications. He tried holding it against his hand, and the device worked fine. The only difference? The arm he wore the Watch on was heavily tattooed. Once he placed the watch back on his tattooed wrist, it would lock up again.
A possible explanation is put forth by another Redditor:
“Oxyhemoglobin has several local peaks of absorbance which can be used for pulse oximetry: one green, one yellow, one infrared, etc. Apple uses the ones at infrared and green parts of the spectrum. Now, here’s some key facts. Melanin and ink are both equally good at absorbing frequencies over 500nm, which sadly includes the green. But, melanin’s absorbance falls down so rapidly that by the infrared end of the spectrum its hardly absorbing anything at all. That, combined with the fact that Apple adjusts the sensitivity/light level dynamically means infrared is probably black people friendly. Ink has a much more gradual fall off, so even infrared might not work for them.”
Users who would turn off the wrist detection feature to get notifications back will find that Apple Pay no longer works. No word yet from Apple on the issue.
How about our readers? Are any of you heavily tattooed on your wrist area? Have you experienced similar issues with your Apple Watch? Please share your experiences in the comments section below.