A Framework of a Process Modelling and Optimization System for the Design, Fabrication and Evaluation of Progressive Lenses

摘要

To provide a clear and comfortable intermediate vision for presbyopic patients, there is a growing need to replace the traditional single vision, bifocal and trifocal lenses by Progressive Addition Lenses (PAL) with a small interval of degree. They are mainly tailor-made and expensive. Injection moulding of PALs is suggested in this paper to reduce the cost, so that more people can afford to have one. Ultra-precision freeform polishing (UPFP) is a technology that can machine precision moulds with sub-micrometer form accuracy and surface finish in nanometer range. In this paper, a framework of a process modelling and optimization system is presented for supporting the design, fabrication and measurement. A pilot experiment has been done to verify the framework and encouraging results have been obtained.