Why do I see a circle of static in the center of my vision? Is it visual snow?

See an eye doctor. If the spot you are seeing is constantly present, you should have it examined as soon as possible. Occasional spots of this nature are often normal, but one that is central and does not disappear should be evaluated to rule out issues with the retina (the film layer of the eye).
Possible migraine. This sensation may be due to migraine if associated with headache. Sometimes there is no associated headache and it is referred to as ocular migraine. A complete eye examination is required to exclude other eye diseases of the cornea, retina, or optic nerve that can also cause this symptom.
Central vision defec. The center of vision is concerned with the macula of the eye. This problem requires an examination by an opthalmalogist to determine what is happening to the macula portion of the retina.