Cutting a lens takes practice.
Cutting a spectacle lens to fit into a frame is called finishing. The Opticianworks training manual notes that a lens starts out as a round, thick chunk of plastic or glass. Long ago, the cutting process was done by hand, and took a long time. Today, machines called edgers do the cutting work, but you still need to know operate the machine during the lens cutting process. Each manufacturer's edging machine is a little different; check your particular machine's manufacturer's manual for any specific steps for lens cutting if you are unsure of the process.
Instructions
1. Start with an uncut lens blank that matches the lens prescription. Verify the lens power with your lensometer, an optical tool that registers lens prescriptions. Keep the lens clean while you work. A September, 2007 article in "20/20" magazine notes that clean lenses are crucial for a good finishing process. The article suggests holding the lenses by the edges to avoid getting fingerprints or dirt on the lenses while they're being cut.
2. Apply blocking tape, a material that helps hold the lens in the machine. Open the machine, and attach the lens to the block. The block holds the lens in place while the machine cuts down the blank.
3. Input patient prescription information into the machine. Press start. Wait for the cutting process to finish, usually less than a minute. The machine automatically stops when the cutting is completed.
4. Open the machine, and remove the lens from the edger. Remove the lens from the block. Remove the blocking tape from the lens. Wipe the lens clean.
5. Insert the lens into the frame. Place the lens in the lensometer, and verify the lens prescription one last time.
Tags: cutting process, blocking tape, into frame, lens clean, lens cutting