The production of finely-tuned optical lenses and prisms - used in cameras, telescopes and semiconductor manufacturing equipment - necessitates the sensitive touch of the human hand. Akira Hozumi produces prototype optical lenses and pentaprisms, which then become the standard for mass-produced goods. He uses his hands, fingertips and a sense of timing and intuition that has been honed over the years to produce these articles, some with angles to within 1/360 of a degree.