dessiller

A literary verb almost always used in the fixed figurative expression dessiller les yeux de quelqu'un — to open someone's eyes to a truth they had been ignoring or refusing to see. It comes from falconry: cillait originally meant sewing a training falcon's eyelids shut, and dessiller was unstitching them once training was complete.

• Cette révélation lui a dessillé les yeux sur son entourage. — That revelation opened his eyes about the people around him.
• Il a fallu cet échec pour lui dessiller les yeux. — It took that failure to finally open his eyes.
• Ses conseils m'ont dessillé les yeux sur mes propres erreurs. — His advice opened my eyes to my own mistakes.

This verb essentially only survives in the fixed expression dessiller les yeux — using it outside that phrase, or with a different object, will sound odd or archaic to a native speaker.

• expression Dessiller les yeux — A literary idiom rooted in medieval falconry — cillait meant sewing shut a training falcon's eyelids, and dessiller was unstitching them once training was complete, giving the modern figurative sense of opening someone's eyes to a truth.