Pop eye Question

In the beginning of December, my foxface developed pop eyein one; and
Cloudy eye in the other. I placed him in a QT and gave him and began the
treatment. The product says I could give him the medicine for a maximum
of 10 days (2 five day treatments). After the 10 days I did 2 partial
water changes and left him in there for 2 weeks. The pop eye is still
not back to normal, so i began his treatment again. From what I've read
his eye may never go back to the way it should be because the muscle was
stretched. So how can I tell if he's better or not?