R.J.
Sometimes all it takes to fix eyes are wearing the glasses to train the muscles slowly outwards. Other times there is NO amount of muscle strengthening / training that will fix it. BUT with the surgery the vast majority will be taken care of and THEN the muscles can be trained once they've been tightened/loosened to get things "close".
Think of it like breaking a bone at a 90 degree angle. Sometimes it can just be set, sometimes it required surgery to set correctly. Even with the surgery there is recovery time in the cast... and once it's removed... there's still physical therapy. We can't put a cast on eyes to hold them where they need to be... but the glasses are the next best thing. Combo of cast + physical therapy.