Cov iav aspheric cylindrical feem ntau yog semi-cylindrical. Piv nrog rau cov iav, cov iav cylindrical sib sau ua ke lossis sib cais lub teeb pom kev raws txoj kab focal es tsis yog qhov focal, uas yog siv dav hauv ntau yam lag luam thiab teb xws li cov cuab yeej siv kho qhov muag, cov khoom siv thaij duab, kev sib txuas lus kho qhov muag, kev thaij duab kho mob, kev ua laser thiab lwm yam. Nws muab cov txiaj ntsig ntawm cov iav aspherical thiab cov iav cylindrical ua ke, thiab muab cov cuab yeej muaj zog rau cov neeg tsim kho qhov muag los ua kom zoo dua qhov kev ua tau zoo ntawm lub cev kho qhov muag, txo qhov aberration thiab txhim kho qhov zoo ntawm cov duab. Nws qhov kev ua tau zoo ntawm qhov muag yog cuam tshuam nrog cov ntaub ntawv. Cov iav aspherical cylindrical iav yog siv dav hauv cov kab ke kho qhov muag thiab cov khoom siv kho mob vim nws qhov kev ua tau zoo ntawm qhov muag thiab kev ua haujlwm ntev.
Wavelength tau tsom mus rau kev muab cov khoom siv kho qhov muag siab rau 20 xyoo