astigmatism
astigmatism — noun
1. a medical condition in which the front surface of the eye is not evenly curved,
a medical condition in which the front surface of the eye is not evenly curved, so objects at any distance appear unclear, stretched, or out of focus
Mei's eye doctor told her that her astigmatism could be corrected with special contact lenses.
corrected with contact lenses
A routine eye test showed that Hugo has mild astigmatism in both eyes.
Children with undiagnosed astigmatism may struggle to read the board at school.
Anong had laser surgery to fix the astigmatism and no longer needs glasses.
Heloísa's astigmatism made road signs hard to read while she drove at night.
- blurred vision
describes the symptom rather than the underlying eye condition; less precise
文法句型
have/develop astigmatism
be diagnosed with astigmatism
correct astigmatism
用法筆記
Frequently used without an article: 'She has astigmatism.' With an article ('the astigmatism') it refers to a specific case, as in 'the astigmatism in his right eye.'
常見錯誤
2. a defect in an optical device such as a camera, microscope, or telescope in whic
a defect in an optical device such as a camera, microscope, or telescope in which the lens or mirror cannot focus all the light from a single point onto one sharp dot, so parts of the image stay blurry no matter how the focus is adjusted
Devika's new camera lens had astigmatism, so no matter how carefully she adjusted the focus, the edges stayed blurry.
astigmatism in camera lenses
Minho returned the telescope because astigmatism in its main lens made stars appear stretched.
Astrid adjusted the projector's focus wheel, but astigmatism in the lens kept the text at the edges looking stretched.
The technician at the camera shop said astigmatism in the wide-angle lens was causing uneven sharpness across the photos.
- lens aberration
broader term that includes astigmatism along with other optical faults
文法句型
astigmatism in [optical device]
reduce astigmatism
cause astigmatism
用法筆記
In optics, 'astigmatism' is one of several lens aberrations (along with spherical aberration and coma). It is an uncountable noun even when describing a specific device: 'the lens has astigmatism.'