The sudden and absolute loss of a wicked person's assets serves as a stark reminder of how fragile material wealth truly is. Whether this loss happens during his lifetime or at the exact moment of his death, his fortune vanishes in an instant.
One perspective focuses on the tragedy striking while the wealthy man is still alive. He goes to sleep or takes to his sickbed surrounded by his riches, and he does not physically pass away [אבן עזרא, מצודת דוד, אלשיך]. Yet, when he opens his eyes and wakes from his slumber or illness, he discovers a devastating new reality. Overnight, his entire fortune has been lost or stolen, leaving him completely destitute. Because living in absolute poverty is conceptually likened to death, he effectively goes to sleep alive and wakes up in a state where he is considered dead [אלשיך, מצודת דוד, ביאור שטיינזלץ].
Alternatively, this sudden loss occurs at the actual moment of the rich man's physical death. In this scenario, he dies while still in possession of his wealth, but he meets a shameful end and is denied a proper burial [רש"י, מלבי"ם]. His tragedy extends beyond his own unburied body; his fortune is never collected by his heirs, as his children die before they even have the chance to inherit it [רמב"ן].
The idea of opening the eyes and finding nothing left is also understood through two distinct lenses related to death. From the perspective of the deceased man himself, if he were able to open his eyes immediately after dying and see his estate in ruins, he would recognize that he has departed from the world. Consequently, he would feel no sadness over the loss of property he no longer needs [מלבי"ם]. From the perspective of an onlooker, the disappearance is absolute. Anyone who opens their eyes to search for this once-wealthy man will find that he has vanished completely, as though he never existed at all [רמב"ן].