Contacts need to fit. It is very important that an eye care professional fits your contact lenses, even if they are only worn for cosmetic purposes and don't have any "power." you can get serious eye issues if the lenses are not fit properly to your eyes. If you haven't been fit or evaluated by an eye care professional, please do so. I agree it could also be dry eye.
Oxygen! You may be experiencing a problem called hypoxia, where not enough oxygen gets to the cells of the cornea. Patients will often say that their vision is foggy, like after swimming with their eyes open. The lack of oxygen causes swelling of the cornea, which is the surface where your lenses rest on your eye.