What's wrong with my dog's eye?

This morning my dad took my dog outside and it found a frog or toad that it started pawing at. A few hours later I took him outside and noticed that he was squinting in his right eye, and his pupil was severely constricted in that eye. I took him to the vet and they ran some blood tests and nothing came back positive, also the vet said it could be a CNS problem but that it was unlikely because his pupil was reacting a little to the light still.

It's been about 12 hrs and his pupil is back to its normal size, but appears a little cloudy in the middle. Also, now that he's not squinting you can see the sclera of his eye is a little red.

Does anyone know of any poisonous frogs or toads that can do this? I live in Florida and researched a little on the cane toad, but it seems like the reaction would have been more severe if it was a cane toad.

Also, does anyone have any experience with something similar happening to their dog?

Do you know if the cloudiness will go away, or if he'll have any lasting damage from this?

Does

What's PLR?

...Pupil light reaction? or something? i don't know either...i saw a different vet than I normally go to since they were fitting me in to be seen right away. He didnt seem to know what he was doing. he wasn't even examining the correct eye when he first came in the room, and started explaining things that were wrong with his normal eye (which was perfectly fine! normal!). It was a little ridiculous...