My loss of vision in left eye

I had a father, mother, & brother in which none of them ever had to wear glasses nor any vision enhancements. I have lost vision in my left eye and I am scared to death that I will lose sight in my right eye. I have a doctor at the VA who has prescribed a new pair of glasses. I have always been near sighted and several years ago I had cataract surgery giving me distance correction and that is where I am nervous.