astigmatism
英 [ə'stɪgmətɪz(ə)m]
美[ə'stɪɡmətɪzəm]
- n. [眼科] 散光；[光][电子] 像散性；[光][电子] 像散现象
英英释意
- 1. (ophthalmology) impaired eyesight resulting usually from irregular conformation of the cornea
- 2. (optics) defect in an optical system in which light rays from a single point fail to converge in a single focal point