«اِلْعَمَى يَا بَدْرْ»

The saying comments on a person who misses something perfectly obvious. Whatever they overlooked was as conspicuous as a full moon (badr, here the moon, not the personal name) in a clear night sky, yet they did not register it, either because their mind wandered or because their eyes had already settled on something else.

The humor lies in turning toward the moon itself and offering it an excuse: its brightness is not at fault, since the failure belongs entirely to the observer. In effect, the speaker gently ridicules the oversight by treating it as a figurative, temporary blindness, meaning a lapse of attention rather than a literal disability.

Use it as a wry aside when someone has walked past, searched around, or failed to notice something plainly in view, for example an item right in front of them or an evident fact, because their attention was elsewhere.