Yep, it happens to me all the time. Two years ago when I had been in a Fibro flare for almost 3 months (great fun) my body began "giving up" and almost shut down my pancreas and kidneys. Discovered in a matter of days my blood sugar when nuts from a daily score of around 110 to 476. Now I have type 2 Diabetes. Optometrist said that even though I now have my blood sugar under control I'll have days where my vision is blurry and need to wear my glasses and other days when I won't. I too felt a little funny, but told him it appeared my "contrast" like for my TV was shot and I had little depth for lack of a better way to explain it. Everything appeared neutral. Doctor said that once my blood sugar remained between 105-140 my normal vision would return. And it did. However, occasionally, later in the evening, as my eyes tire, the blurred vision returns. Good night sleep, as best any of us with Fibro can experience, and everything is normal again.