A dramatic turning point in the campaign of the Aramean army occurs the moment the soldiers discover their true location. After being led far from their intended path, they suddenly find themselves in the very heart of the enemy capital.
Elisha asks God to open the eyes of the soldiers. This plea is not a request for a medical cure from physical blindness, but rather a request to lift the state of sensory disorientation that had been cast upon them earlier [מצודת דוד]. The concept of opening their eyes represents a return of knowledge and awareness. The Aramean soldiers never actually lost their physical vision. Instead, they suffered from a deep mental confusion that stripped them of the ability to recognize their surroundings. Only when this confusion is removed and their clear consciousness returns are they able to perceive reality accurately [מלבי״ם].
With their clarity of mind restored, the soldiers are confronted with a shocking truth. They realize that they have been guided directly into Samaria, finding themselves completely trapped in the center of the Israelite capital.