Can eustachian tubes cause chronic disequilibrium? if so, can this affect vision? i have allergies, ears feel blocked when swallowing, vng abnormal

Highly unlikely: There has to be major pressure fluctuations such as diving for eustachian dysfunction (etd) to cause imbalance. Chronic disequilibrium is present during movement when there is vestibular weakness as identified on the vng. Vision is used to compensate but shouldn't change. Ear fullness can be from etd, méničre's, tmj, hydrops, reflux. Balance retraining helps when one ear has balance weakness.