Sudden double vision! We have to do?

Respected doctor's My dad suddenly having double vision from last Thursday.We went opthalmologist and checked.They told his blood sugar level is high and it's causing double vision.Also eye doctor advised us to go-to diabetologist.The very next day daddy again checked his sugar levels and met the diabetologist but he ruled out sugar and told to do excercise regularly.but still my dad having double vision.he's taking neuronik plus vitamin tablet prescribed by the Opthalmologist.He don't have any other symptoms except double vision and slightly blurred vision.for your kind information opthalmologist told dad is having double vision on right eye and it's because of a nerve which causing him to not move his eye fully to the right side(only right eye).Now what we have to do ??please reply 🙏🙏 I have attached both the blood reports