Well I haven't had any issues so far with my red eyes, but I will try to help.
As far as the injury, is it possible he got bit by a cricket while trying to eat it?
Possibly the crickets are too large? They should be the size of the distance between the frogs eyes. I know I have an issue with my pet shop, their smalls are too small and the mediums are almost winged like the large. Today I had to just take double the amount of smalls since I didn't want to risk impaction or bites with the mediums.
As long as the temps are correct and humidity are good, the next thing is possibly the substrate is staying too wet? Are you feeding in the tank or out? If in, is there something that it could have swallowed (usually a substrate) and got impacted?
I think they can go several days without eating so I wouldn't get too worried too soon. Check to see if you're still finding poo, that's always a good sign.