That comet is invisible to the unaided eye.

那颗彗星只用肉眼是看不到的。

youdao

Barnard's Loop is too faint to be identified with the unaided eye.

巴纳德环太昏暗以致肉眼无法辨认。

youdao

Barnard's Loop is too faint to be identified with the unaided eye.

巴纳德环太昏暗以致肉眼无法辨认。

youdao