(ophthalmology) impaired eyesight resulting usually from irregular conformation of the cornea
同义词：astigmatism
(optics) defect in an optical system in which light rays from a single point fail to converge in a single focal point
英汉双解词典包含3185865条英汉词条，基本涵盖了全部常用单词的翻译及用法，是英语学习的有利工具。