Dog Food Versus Sunglass Lens

I was going through some of Shorty's toys in hopes of one day having a garage sale sometime soon, and I came across this huge pair of sunglasses I bought a few weeks ago at Good Will.

I thought it was odd because there was a piece of dog food stuck to them. On closer inspection, I realized that the piece of dog food was actually melted into the lens. I have no idea how the dog food got there, but it did. That's not my concern. My concern is how in the hell does a single piece of dog food eat a hole through the plastic lens of these sunglasses? Is it the dog food? Is it the sunglasses?

The dog food is Wal-Mart brand Ol' Roy Kibbles Chunky 'N Chews and the sunglasses were made in China by Chentian Toys.