‘寸光’ (cùn guāng) literally means ‘inch-light’, evoking the image of light that reaches only an inch—too short to see far. It is a classical, metaphorical term for short-sightedness: the inability to perceive the bigger picture or long-term consequences, often due to narrow focus, self-interest, or lack of foresight. Though not used in everyday casual speech, it appears frequently in formal writing, political commentary, and literary criticism to criticize shallow thinking or myopic decision-making.

The term originates from the idiom ‘目光如豆’ (gāng mù rú dòu, ‘eyes like beans’) and is closely tied to ‘鼠目寸光’ (shǔ mù cùn guāng, ‘rat-eyed inch-light’), which explicitly links short-sightedness to small, timid animals. While ‘寸光’ alone is concise and slightly literary, it carries strong evaluative weight—it’s rarely neutral and usually implies criticism or warning.