coma aberration; coma
Technical term in optics for an off-axis aberration that makes point sources appear comet-shaped.
コマ収差を補正するには非球面レンズが有効です。
Aspherical lenses are effective for correcting coma aberration.
From English 'coma' (from Greek 'kome' meaning hair, referring to the comet-like tail) and 収差 (aberration).