comparing groups -tests applied

I have collected data of 100 patients who had low vision. All these patients were given a specific device and vision was noted before and after giving the device. So, I have to study the acceptance of all these patients with low vision ...whether the patients had good/moderate/poor acceptance with the device. I also need to know the RANGE of improvement in vision(vision before giving device and then after using device)

Im using a stats software called "statistiXL" which i integrated into EXCEL 2007. Is this software reliable?

i have used frequency distribution(descriptive analysis) to find out the sex and age distribution of my study and also find out the most common causes of low vision.

Now how do I proceed from here?I need to find out which type of device is resulting in maximum improvement of vision and also categorize which type of device is most commonly prescribed in a particular cause of low vision.