Which list correctly reflects the steps of lathe cutting?

Which list correctly reflects the steps of lathe cutting?

• A. Spinning, Curing, Hydration, Sterilization, Printing
• B. Melting, Molding, Trimming, Packaging
• C. Lathing, Polishing, Hydration, Extraction, Finishing, Sterilization
• D. Centrifugation, Annealing, Rinsing, Packaging

Answer: (C)

Lathe cutting starts with shaping the lens on a lathe to remove material and form the basic curved surfaces. After the rough shape is created, polishing brings the surfaces to optical quality, removing tool marks and achieving the smooth finish required for comfort and clear vision. For hydrogel lenses, hydration is then needed to bring the polymer to its hydrated state and achieve the correct water content that defines the lens properties. Extraction follows to remove residual processing agents or unreacted materials from the lens material, ensuring safety and stability. Finishing involves final edge trimming and any last surface refinements, and sterilization is the final step to ensure the lens is safe for handling and wear. Other sequences include steps that don’t belong to the lathe-cut workflow, like molding or printing, or place incompatible steps in the wrong order, so they don’t fit the practical manufacturing process.

Lathe cutting starts with shaping the lens on a lathe to remove material and form the basic curved surfaces. After the rough shape is created, polishing brings the surfaces to optical quality, removing tool marks and achieving the smooth finish required for comfort and clear vision. For hydrogel lenses, hydration is then needed to bring the polymer to its hydrated state and achieve the correct water content that defines the lens properties. Extraction follows to remove residual processing agents or unreacted materials from the lens material, ensuring safety and stability. Finishing involves final edge trimming and any last surface refinements, and sterilization is the final step to ensure the lens is safe for handling and wear. Other sequences include steps that don’t belong to the lathe-cut workflow, like molding or printing, or place incompatible steps in the wrong order, so they don’t fit the practical manufacturing process.