You probably already know this, this is not new. But it's quite fascinating isn't it? How many times do you unlock your device? According to Apple, about ~80 times a day. Every time you unlock your device, the dot projector shoots 30,000 lasers straight into your face and eyes to map your accurate facial geometry. You probably know the old saying about lasers? Anyway, it's completely safe according to Apple, as the the VCSEL used in iPhones emit only the healthy kind of lasers. So you should be good. It is proven to be completely safe; I strongly believe in what Apple says. Go Face-ID! Screw Touch-ID.