A professional who affixes precision optical or ophthalmic lens blanks in metal blocks used to hold blanks during grinding and polishing operations. Responsibilities include:

• Selects blocks according to size of lens blank and heats blocks or lenses over gas burner to prepare for adherence of pitch or wax.
• Pours molten pitch into block, using ladle, or melts wax over holding surface of block, using torch.
• Presses and centers lens blank into wax or pitch.
• Pushes lens to test for adherence to block and positions blocked lens under fan for cooling.
• May smooth and remove sharp edges from lens, using grinding wheel.
• May test centering of lens in block, using lapping machine.