You need to see (1) an endochonologist (not an opthamologist) as square one and initiate a program of diet and medications and daily monitoring of glucose. Square two is to see (2) An opthamologist who will perform as fundascopic examination to determine if there is any damage.
It can take weeks for your eye sight to return to normal after you get your BG down. since its only one eye that is blurry I would see an Opthermoligest asap