Many tattooed owners of Apple watch argue that the problem
arose because the ink from the tattoo prevents the watch to detect the user's
hand, which is why It self locking. One user said that he thought it was
broken, because It did not function when he put it on the wrist. However, every
time he switches to the body part that is not covered with tattoos, the smart
watch work.
While detecting the wrist can be excluded, the watch can make it less safe and prevent
the use of many useful functions such as Apple play. One user Redita believes
that the problem is in the way the sensors register the color of the tattoo,
especially if they are dark. Otherwise, they use light to read the heart rate
and recognize that the user wears a watch. Since dark tattoos absorb light, the
clock hardly ever read the presence of the user.
Melanin, the pigment that gives skin its color, otherwise
reflects infrared light, which means that the problem does not occur in people
naturally darker.