Is my dogs blindness temporary?

I have a 3 year old female Shih Tzu. She has gone blind in one of her eyes and I believe its from an injury to it. I have a cat that doesn't like her that much and he scratched her in the eye. I just noticed it Sunday. Her eyes was red and there is a visible scratch and it was kinda blue and cloudy. Today its is completely blue and cloudy. Is this the way the eye heals or is the permanent? I really hope not:(