Gan Ying was a crack shot in ancient times. Once he pulled his bow, the animals he shot at would fall and the birds he shot at would drop. He hit the target with every shot. His disciple, named Fei Wei, learned diligently and practised hard, and surpassed his teacher in archery.
A man named Ji Chang came to Fei Wei to learn archery. Fei Wei said to Ji Chang:
"You must first train your eyes not to blink. Then I can talk with you about archery."
Ji Chang returned home. Following Fei Wei's instructions, he lay face up under his wife's loom, with his eyes fixed on the foot tweezers moving up and down.
After training in this way for two years, his eyes would not blink even when an awl was flying towards them. Ji Chang gladly reported the result of his training to Fei Wei.
Fei Wei said:
"This is not enough. You must train your eyesight, then we can talk about archery. You must train till you can magnify small things into big ones, and see minute things distinctly."
Ji Chang returned home and hung a louse on the window with an ox tailhair. Every day he faced south and stared at it with fixed concentration. Over 10 days later, he felt that the louse was becoming bigger. After 3 years, it looked as big as a carriage wheel. Then he looked at other things and they became as big as small hills in his eyes.
Thereupon, he took an arrow and shot at the louse. He hit the center of the louse with one single shot, while the ox tailhair was untouched and still hanging on the window.
Ji Chang ran to tell this to Fei Wei. Fei Wei gladly patted him on the chest and said:
"You have really mastered the skill of archery."