An integrated approach for design, ultraprecision polishing, and measurement of freeform progressive lenses

The importance of presbyopia is that it affects 100% of people at their late adulthood and it starts to show up at 40s. The market for high quality progressive lenses is very large. There is a growing need for freeform progressive lenses with a small interval of degree to provide a clear and comfortable intermediate vision for presbyopic patients. Due to the lack of adequate design and manufacturing capability, most of the freeform progressive lenses are designed and imported from overseas at a high price and with long delivery time. This paper presents an integrated approach for supporting design, fabrication and measurement of freeform progressive lenses. A prototype of an integrated system has been developed based on key technologies including an advanced optics design method, computer controlled ultra-precision polishing (CCUP), precision injection moulding, as well as a new freeform surface characterization method. A prototype system has been built and experimental verified successfully through a series of experiments. Successful development of the system will provide an important means for optometry research of freeform progressive lenses.