Distorted anatomy. If you have a distorted macula (retina) anatomy, it can result in wavy vision. The more common causes of distorted maculas are macular degeneration, epiretinal membrane, and macular edema.
Simple or complex. It maybe something simple as getting up too fast and your blood pressure being a bit low and cause reduced blood flow to your head- called orthostatic hypotension. Another simple reason is protein debris on the tear film, very common in the morning that is usually blinked or washed away. If you have this with any other neurologic signs- difficulty talking, holding objects, walking -go to your md.