The most common reason for blurry vision after waking up from sleep (assuming this gets better after a few minutes) is having some dried out tear secretions floating around on the surface of the eye. This happens in most people, and is part of the reason that many people "rub their eyes" when they wake up; they are trying (unconsciously most likely) to clear up their vision by removing these secretions.
Another common cause would be eye allergies, or allergic conjunctivitis. Allergic conjunctivitis symptoms (itching, burning, watering, and redness of the eyes) are often worse when getting up from sleeping, especially if the person is allergic to dust, mold or mites, as these tend to be concentrated in the mattress, blankets, and pillows.
I would mention this problem to your primary care doctor
or your eye doctor
. They can check out your eyes and your vision to make sure there is nothing going on. If the symptoms of blurriness do not resolve during the day, or if you have other concerning symptoms such as floating spots or flashing lights before the eyes, then you need to see a doctor right away!