Tomaten auf den Augen haben

Literally: To have tomatoes on one's eyes

Example: “Der Schlüssel lag direkt vor ihm; er hatte wohl Tomaten auf den Augen.” — The key was right in front of him; he really couldn't see the forest for the trees.

Origin: No single theory is confirmed, and three genuinely different explanations compete. One ties the phrase, documented in use since around 1920, to the swollen, reddened eyelids of someone who looks half-asleep or hasn't fully woken up — red and puffy enough to resemble tomatoes. A second, more elaborate theory reaches for medieval Spain, where the tomato was long regarded as a "fruit of sin," and tomates en los ojos is claimed to have been an actual public punishment for traitors, thieves, or adulterers, forced to wear tomatoes bound over their eyes for weeks or months as a mark of disgrace — though this specific historical claim isn't well documented. A third, considerably more mundane theory points to early traffic police: when automatic signals were still new and unfamiliar, an officer stationed at an intersection might shout at a driver who failed to move on green, Sie haben wohl Tomaten auf den Augen! — you must have tomatoes on your eyes.