What is the purpose of using a facet on high-minus lenses?

The purpose of using a facet on high-minus lenses is to reduce edge thickness and weight. High-minus lenses are prescribed for individuals with significant myopia, meaning their prescription requires the lenses to be thinner at the center and thicker at the edges. By incorporating facets, which are small flat surfaces cut into the edge of the lens, the overall thickness at the edges is minimized. This design also contributes to a lighter weight, making the lenses more comfortable to wear for the individual.

Reducing edge thickness not only improves the aesthetic appearance of the lenses, making them less bulky, but it also helps in lowering the overall weight, making them more practical for everyday use. Such considerations are particularly important in high-minus prescriptions, where thickness can significantly affect both comfort and cosmetic appeal. Thus, facets play a crucial role in enhancing the user experience while maintaining the necessary optical correctness of the lens.