1964-442/1/1
- Object Number:
- 1964-442/1/1
- Image ©
- The Board of Trustees of the Science Museum
six stages in making fused tri-focal lenses (1) the segments are placed together, (2) segments fused together, and on to lens blank, (3) front surface of the compound lens is ground, (4) front surface of the compound lens polished, (5) lens cut to shape and bevelled, (6) plastic lenses mounted in spectacle frame. Supplied by Bateman, Frederick and Co (see note).