This was an interesting story about the determination of skin aging. According to the report, scientists used a harmonic generation microscope to determine the intrinsic age of skin. The intrinsic age is the genetic age of the skin. They looked at skin that was not normally exposed to UV which can accelerate aging.
The technique could be used to test future anti-aging ingredients.
It can also be used to determine the exact age of someone. I wonder if this means IDs to prove age could eventually become a thing of the past.