keen eyesight; superior vision
Archaic idiomatic expression referring to exceptionally sharp eyesight, derived from the legendary figure Lilou in ancient Chinese folklore. Used in classical or literary contexts.
His powers of observation can truly be called the keen eyesight of Lilou.
From the Chinese legend of Lilou (離婁), a figure renowned for his exceptional eyesight. The expression is used in classical Japanese to praise someone's sharp vision.