Hens go broody when you don’t want them to… and won’t go broody when you do. 
Welcome to BYC. Please go to your original post about your blind duck; there are suggestions on it.
I have Muscovy femae who is blind in one eye, and it looks perfectly normal and a female Runner who is blind in one eye, and you can definitely tell it's cloudy
I have Muscovy femae who is blind in one eye, and it looks perfectly normal and a female Runner who is blind in one eye, and you can definitely tell it's cloudy