Sinus can affect your eyesight?

Can: There are multiple sinus cavities including the ethmoid and paranasal which are in direct path with your eye orbit, so if there is severe congestion, swelling and blockage, it may contribute to problems with vision and movement of the eye.

Yes: Yes. Severe sinus infections can cause blurred vision either due to headache/ pain symptoms or in severe cases direct involvement of the optic nerve or orbit.