From a UK ATC point of view, yes you can, RVR 800m is the cut off for Visual Approaches.
ATC will not approve a Visual Approach when the RVR is less than 800m, if the pilot did request so then ATC should inform the pilot that this type of approach is unavailable and request the pilot's intentions.
I have often had pilots cancel IFR and go VFR to 'cut the corner'.