Assertion: astigmatism | /r/HasProperty | aberration
Facets:
value: in optics
type: LOCATION
Source sentences:
text: Astigmatism is an aberration that causes points to blur, degrading sharpness.
text: In optics, astigmatism is an aberration in which an optical system has different focal lengths for ray fans through the entrance pupil at different clocking orientations.