an·as·tig·mat /æˈnæstɪgˌmæt, ˌænəˈstɪg-/
無象散透鏡
an·astig·mat /æˈnæstɪgˌmæt, ˌænəˈstɪg-/ 名詞
消像散透鏡,去像散透鏡
anastigmat
n : compound lens or lens system designed to be free of
astigmatism and able to form approximately point images