Apple Watch Might Not Like Your Tattoos As Much As You Do

Do you have a sleeve full of beautiful tattoo artwork on your arm? Are you one of the lucky ones that received your Apple Watch preorder on April 24th? Well according to some reports on Twitter and Reddit, you may be in trouble. Or more to the point, you might be having trouble using your Apple Watch.

The problem is with the way the watch senses whether or not you are wearing it. Once you put it on and enter your passcode to allow it to pair and communicate with your iPhone, the watch continuously monitors whether or not it has remained pressed up against your skin. It does this by monitoring your heart rate using rapidly flashing infrared and green light from transmitters on the back of the watch. The light penetrates your skin and can actually “see” the amount of blood that is inside your wrist at any given moment. In between heartbeats, there is less blood in your wrist and the device can use these measurements to calculate your heart rate.

Tattoo-ArmApparently, some tattooed users are reporting that the heart rate sensor does not function properly on their wrists. Tattoos that are heavy in red and dark black seem to be causing the most issues, which makes sense because the red ink absorbs the green light just like your red blood cells do, and black can absorb both green and infrared light.

What’s perhaps more interesting, is that users with exceptionally dark skin are not reporting these problems. Apple no doubt conducted extensive testing of this feature before the device was approved for mass production, so this issue could be something that was missed during quality control testing.

Users who are experiencing this problem will likely to become frustrated with the Apple Watch very quickly as many of its functions such as Apple Pay, Voice activated phone calls, and notifications all rely on the heart rate sensor to verify that an authorized user who has entered their pass code and confirmed their identity has not taken the watch off.

The bottom line is that one of the main security precautions that the Apple Watch depends on is insuring that the watch has never left an authorized user’s wrist once their identity has been confirmed. This allows them to receive applications, place phone calls, and use Apple Pay to make purchases with their watch. If the watch is constantly incorrectly detecting that it has been removed from the person’s wrist, it will be very difficult to use these features. Apparently it is possible to disable the wrist detection in order to allow the watch to receive notifications, but in this scenario Apple Pay and phone calls will not work.

At this time, Apple has not officially commented on this possible issue.