Surgery and Healing in the Developing World - Dartmouth-Hitchcock

Ophthalmology
Figure 6. Axis determination.
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Lens Size Approximation
Place the lens against the frame in the correct position. The marked axis line
should be parallel to the horizontal axis of the frame and in the center of the vertical
axis. The lens shape required can then be indicated using a permanent marker to
draw around the inside of the glasses.
Cutting
The diamond-tipped pen should be used to score around the outside of the
desired lens shape (Fig. 7). Once complete the pliers should be used to remove the
outer portion of the lens (practice first with plain glass).
Shaping
A diamond-coated glass grinder is used for finishing the edges of the lens. Great
care should be taken not to overgrind the lens. Determine the correct shape by
comparing with the frame regularly. No sharp edges should be left on the lens.
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