This idiom means adding the finishing touch that brings something to life.
Gǔ shíhou yǒu gè huàjiā jiào Zhāng Sēngyáo
古时候Gǔ shíhou🔊，有个yǒu gè🔊画家huàjiā🔊叫jiào🔊张僧繇Zhāng Sēngyáo🔊。
Tā zài sìmiào de qiáng shàng huà le sì tiáo lóng
他Tā🔊在zài🔊寺庙的sìmiào de🔊墙上qiáng shàng🔊画了huà le🔊四条sì tiáo🔊龙lóng🔊。
Lóng huà de fēicháng bīzhēn dàn dōu méiyǒu huà yǎnjīng
龙Lóng🔊画得huà de🔊非常fēicháng🔊逼真bīzhēn🔊，但dàn🔊都dōu🔊没有méiyǒu🔊画huà🔊眼睛yǎnjīng🔊。
Yǒu rén wèn tā wèishénme bù huà yǎnjīng
有人Yǒu rén🔊问他wèn tā🔊：为什么wèishénme🔊不画bù huà🔊眼睛yǎnjīng🔊？
Tā shuō huà shàng yǎnjīng lóng jiù huì fēi zǒu
他说Tā shuō🔊：画上huà shàng🔊眼睛yǎnjīng🔊，龙lóng🔊就jiù🔊会huì🔊飞走fēi zǒu🔊。
Dàjiā bù xìn fēi yào tā huà
大家Dàjiā🔊不信bù xìn🔊，非要fēi yào🔊他tā🔊画huà🔊。
Tā gāng gěi liǎng tiáo lóng diǎn shàng yǎnjīng qiáng shàng de lóng jiù pò bì fēi qù le
他Tā🔊刚给gāng gěi🔊两条liǎng tiáo🔊龙lóng🔊点上diǎn shàng🔊眼睛yǎnjīng🔊，墙上的qiáng shàng de🔊龙lóng🔊就jiù🔊破壁pò bì🔊飞去了fēi qù le🔊。
English Translation:
In ancient times, there was a painter named Zhang Sengyao. He painted four dragons on a temple wall. The dragons looked very lifelike, but none had eyes. Someone asked: "Why not paint the eyes?" He said: "If I paint the eyes, the dragons will fly away." No one believed him and insisted. As soon as he painted eyes on two dragons, they broke through the wall and flew away.