Don't pull the wool over my eyes

Origin

The vivid image behind 'pulling the wool over someone's eyes' draws directly from the literal act of obscuring vision. Imagine a thick piece of wool, perhaps from a sheep, used to blindfold someone or obstruct their view, making it impossible for them to discern what is happening. This physical act of rendering someone temporarily sightless to gain an advantage or commit a deception became a powerful and easily understood metaphor. By the 19th century, this visual shorthand had fully migrated into common English idiom, evolving from a potentially real act of blinding into a universally understood expression for trickery and deceit, warning others not to be fooled.