In my case, running sugars in the 400's caused me to have visual problems. I had trouble seeing signs while driving. Some days I couldn't see the type on my computer screen without cranking up the zoom. My normal glasses always seemed to be dirty and filmy- but they really weren't. I thought I was just getting old and needed a new prescription.
I had pressure from the high sugars in the back of my eye and in the front. I had microaneurisms (bleeding) and beading all over my eyes. Keeping my sugar under 100 at all times has caused the pressure to go away. I had a laser procedure to stop the bleeding. I will need several more clean-ups before the problem is quenched-
My eye surgeon told me that its NOT unusual to see people with pre-diabetes come in with the same type of problems. She thinks that anyone that has sugars running over 100 should be diagnosed as diabetic- and immediately scheduled for a fully dilated eye exam.
One lady in my hospital support group woke up one morning and literally couldn't see a thing- like a white cloud over her eyes and not able to focus, not dark- but fuzzy- she went to her doctor and found out she was a diabetic.
Other than the microaneurisms- my vision is fine now. I actually needed a lesser prescription after my eyes settled down.
I just want to live happily ever after-every now and then. Jimmy Buffett