There is surgery but it is extremely expensive. Only specialized vets do the surgery. My adopted Eskimo Spitz came to me with developing Cataracts. He is also mostly deaf. However, I cleaned his ears out and used ear wax remover. He hears much better!
Dirtnap also has conjunctive eye that runs goo out of it. I have to clean it almost everyday. There are treatments of eye drops but some cases they don't work. Dirtnap is one of those cases. He doesn't seem to mind the eye salve at all it just doesn't clear up the condition.
I wish I could give some encouraging news but you may want to talk to a regular opthamologist on cataract advice. Not sure if more light helps see better or not. I don't believe the animals are completely blind with cataracts just cloudy vision.
Also watch on petting approaches. Dirtnap will flinch when approached toward his head. I let him smell me BEFORE touching! It relaxes him. If you dog does snap at you, remember it can't see objects as well. Your hand may look like something is going to hurt it. Warn children to let the dog smell before touching. It is a natural reaction for them to smell first anyways. Good luck!!!