Functional endoscopic sinus surgery is performed with telescopes and image guidance system to remove polyps inside the sinuses. The polyps can be located in the sinus cavities between the eyes, known as the ethmoid sinuses. It is exceedingly rare to go blind after endoscopic sinus surgery. It is also best to get a second or third opinion to discuss the risks. Make sure you bring the CAT scans of your sinuses with you to the other appointments. For more information and diagrams explaining endoscopic sinus surgery, please see the link below
Endoscopic Sinus Surgery and Polypectomy is a very safe surgery. It involves operating in a narrow space between the eyes and at the base of the brain. The bone between the sinuses and the eyes is very thin and the optic nerve for vision is also close by. There are image guided techniques that allow for additional safety with the procedure. That being said, the consent form includes all possible risks including change in vision, blindness, CSF leak Etc. These are extremely unlikely. Please follow up with your surgeon or obtain a second opinion if you are not comfortable with your concerns
I saw this question and could not help but respond. It would be in your best interest to consult with a couple of well respected ENT doctors before having this surgery. I have never heard of such a thing, but I do not know your medical history.