How does the Geneva lens clock work?

The Geneva lens clock functions by assessing the curvature radius of the lens surface. This tool is essential for measuring the front and back curves of a lens, which helps in determining its power and ensuring proper fitting in eyewear.

The device operates on the principle of mechanical linkage, where it utilizes a series of arms and a dial. When the clock's arms are placed against the lens surface, the curvature of the lens will cause the opposing arms to move, providing a reading on the scale. This measurement is crucial for ophthalmic technicians to ensure accurate prescriptions and to confirm that lenses are made according to the required specifications.

Understanding the curvature is vital for optimizing visual acuity and comfort for the patient, thus making the Geneva lens clock not just a measuring tool but a significant component in the lens fabrication process.