I Woke Up In The Middle Of The Night Blind

I woke up in the middle of the night blind in my left eye. It returned to normal within a minute or less. I have had no blueness, pain or and lingering affects since. I am a diabetic and have been to the eye doctor in the last 6 months and everything is OK. What do you think? When the vision returned, it was all purple and yellow in the center and gradually went to normal.