I'm sorry you couldn't get help before he died. Trying to find a vet who will see exotic animals is really usually the best thing we can recommend here. There are so many 'invisible' illnesses frogs can get that have to be tested for: fungal infections, bacterial infections...

Apart from the eye I can't tell that anything's wrong with the frog just by looking at it. (I'm not a vet though.) I'd continue to keep an eye on the other one. And I know these questions are boring, but how's the temperature, the humidity? What kind of water do you use (bottled, decholorinated tap, whatever)?