眼镜镜片及角膜接触镜的顶焦度测量

Measurement of vertex power of spectacle lens and contact lens

目的 :国内某些视光学著作 ,将眼镜片或角膜接触镜的顶焦度错误地解释为光焦度 ,由此导致理论和测量工作中的混淆。本文旨在纠正上述错误观点。方法 :从光学的基础定义出发 ,阐述光焦度和顶焦度的差别 ,并对焦度计的测量原理和误差进行正确分析。结果和结论 :眼镜片或角膜接触镜的顶焦度与光学透镜的光焦度是两个不同的定义 ;手动调焦式焦度计的测量误差是固有的、客观存在的 ,与顶焦度和光焦度的定义差异无关。

Objective:In some domestic publications on Optometry and Vision Science, vertex power of spectacle lens or contact lens was misinterpreted as power, thus caused confusion in theoretical and practical measuring work. The purpose of this article is to correct this misunderstanding.Methods:Explain the difference between power and vertex power from basic definitions of optics, and analyze the measuring principle and error of focimeter.Results:As the quality of focimeter is directly related to the vision health of consumers, International Organization of Metrology Legal(OIML) and Chinese government have listed focimeter as compulsive metrological instrument under test.Conclusion:The vertex power of spectacle lens or contact lens is different from the power of optical lens. The measuring error of focimeter with manual focusing is existent and immanent, which has nothing to do with the different definitions between vertex power and power.