How do you prevent "refrigerator fallout"?

In our refrigerator, we put a mini curtain rod a few inches above the bottom shelf that keeps food from spilling out whenever we open the refrigerator door.

We tried a mini curtain rod on the top shelf, but to place the rod in an efficient position, one end has to be on top of the refrigerator light box. The pressure of the curtain rod on the box keeps the light on-off switch from working.

What would work on the top shelf to keep food from spilling out? I'd rather not use a solid plastic bin because that keeps the air from circulating.