Abstract
Since the beginning of this century, popularity of 3C products in our daily life has prematurely influenced and degraded people eye vision. Based on the wavefront measurement data by ophthalmologists, cornea topology has indicated the shape of the cornea is not axis-symmetric; and hence precise measurement on cornea topology is needed for vision correction of myopia or presbyopia eyes. Freeform optics theory has been applied to optometry in vision correction because the design degrees of freedom in free-form spectacles are able to correct presbyopia and astigmatism simultaneously. In this dissertation, the objective is to study how to apply ultra-precision machining with freeform design optometric lenses by manufacture of free-form optical molds. Then, free-form compensation technology has been employed for dimensional errors of lenses for increase in manufacture accuracy so that quality of progressive addition lenses is improved. Initially, mathematical derivation of optical power is established by eye model and wavefront measurement analysis. Then, the freeform tool compensation method based on tool arc-radius selection could reduce the geometric errors of mold surfaces. Free-form compensation technique based on Zernike polynomials expression has hereby been verified experimentally in measurement data with total surface freeform accuracy. Finally, through the use of ultraprecision slow-tool servo diamond turning technology applied on the mold surfaces without final polishing process, injection-molded spectacles with freeform features have been successfully produced for commercial products.