A one-eyed swordsman remains in legend.
The world seen with one eye is hard to grasp in depth.
discerning eye; excellent judgment
Metaphorical use: having a keen, perceptive eye for quality or truth. Often appears in expressions like 隻眼の士 (a person of keen insight).
See also: 一隻眼
He has a discerning eye for art.
A person of keen insight sees ahead of the times.