A Makerspace project:
CD and DVD drives have a laser focusing lens.
This photograph shows the size of the lens next to a ruler. It is an ideal size to fit over some camera phone lens.
Below is the same ruler photographed with the lens in place, showing the MM under the graded scale.
The tip of the screwdriver used to dismantle the CD drive to extract the lens.
With the lens in place, the focal range is so narrow that the lens has to be almost touching the item being photographed, and lighting/focusing is difficult. A motorised focusing arrangement would help.