It might be your contacts' problem. Wearing contacts during sleep will make you feel irritation. Then your eyes will increase the tear flow to fight against the irritation. Overnight, the water in the tears will evaporate and leave a mucous-like film in your eyes, which make your vision cloudy. Usually your cloudy vision will be improved when you blink.
Cloudy vision may be caused by dry eyes due to wearing contacts. Stop wearing contacts for several days if possible. Make sure that the Air condition blast or fan draft does not hit your eyes directly. You can try to use artifical tears like Refresh to relieve it.
It could be caused by dry eyes. Your eyes, in order to fight the irritation of contacts, have increased tear flow. Overnight, some of the water in the tears evaporates, leaving a mucous-like film in the eyes. This may make your vision smeary or cloudy. When you blink, it smears the stuff around, temporarily improving the situation.