Hi, Welcome to JustAnswer. I'm a licensed veterinarian and I'll be happy to help. I'm so sorry to hear about your's and Ben's traumatic experience, but am very glad that Ben is happily living his life otherwise.
When there is a "film" visible to us something in the eye is inflamed or infected or malfunctioning in some way. This "film" could be a cloudy cornea, an anterior uveitis, a cataract, a posterior uveitis, or a detachment of the retina. Has either your vet or the veterinary ophthamologist told you where Ben's problem is located in his eye?
Also, when you look at his eye can you clearly see his pupil? This is the central opening in the iris that you can see in his other eye.
With this information I should be able to better help you. . .