Mr Agastya kolli
Regarding Sinus problem : ENT Surgeon will solve the problem ; most probably by doing FESS (Functional Endoscopic Sinus Surgery
) along with correction of Deviated Nasal Septum
. But you did not mention the age of your father and present diabetic status. both are important to proceed with surgery.
Secondly regarding Dry eyes
: you have already taken enough number of opinions from different Ophthalmologists. even i feel only treatment for that is artificial tears
. keep continue
all the best and take care