As if looking at someone else's eyes

Due to my high blood sugar, my vision is also fluctuating. One day, I could see perfectly well without glasses or contact lenses but the next day, everything is blurry; As of this moment, I am writing this blog with my blurry vision. The weird thing is, when you cover an eye, the other eye can see well. I have to squint or close an eye to see what am I typing. I don't like this.... my vision is importatnt to me.