| Summary: | 碩士 === 逢甲大學 === 電機工程學系 === 104 === This paper proposes a multi-layer structure of RGP contact lenses design for peripheral refractive error correction of myopia. The structure is a combination of free-form、even-aspherical and biconic surface. This article describes contact lenses design procedure to correct visual aberration, such as defocus、coma and astigmatism, from the 〖30〗^° temporal side to the 〖30〗^° nasal side. Compared to a conventional contact lens, our design can simultaneously correct the defocus on central field and peripheral field on the retina. It expands the clear visual scope and avoids the further deterioration of myopia.
The greatest feature of this design is that we combine three layers together. The first surface is biconic for correcting astigmatism, the second is even-aspherical for correcting high-order aberrations, and the third surface is of free-form to correct off-axis defocus at retina, the last surface is spherical with a radius of curvature matching the front surface of cornea. This design provides more flexibility and optimizable parameters to correct high order aberrations, while correcting the defocus on peripheral field. Thus achieve a better visual image quality, finally field at 0°、±10°、±20°、±30° which cutoff frequency is sequentially 110lp/mm, 35lp/mm, 20lp/mm and 15lp/mm of MTF values have reached 0.3.
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