Per the US FAA AIM:
VFR conditions. If the failure occurs in VFR conditions, or if VFR conditions are encountered after the failure, each pilot must continue the flight under VFR and land as soon as practicable.
NOTE -
This procedure also applies when two-way radio failure occurs while operating in Class A airspace. The primary objective of this provision in 14 CFR Section 91.185 is to preclude extended IFR operation by these aircraft within the ATC system. Pilots should recognize that operation under these conditions may unnecessarily as well as adversely affect other users of the airspace, since ATC may be required to reroute or delay other users in order to protect the failure aircraft. However, it is not intended that the requirement to “land as soon as practicable” be construed to mean “as soon as possible.” Pilots retain the prerogative of exercising their best judgment and are not required to land at an unauthorized airport, at an airport unsuitable for the type of aircraft flown, or to land only minutes short of their intended destination.
So if you cannot establish any means of communication (ACARS, etc), you have to decide which is safest: Proceed to filed destination or land somewhere enroute. Unless and until you are assured of VMC from your Flight Level to touchdown, continue as filed. If you reach a "severe clear" area with a suitable airport, then you can make a decision. Realize that an uncleared descent through traffic on a crowded airway could also be disastrous, so the availability of other aids (Transponder, TCAS, etc) will weigh in the decision.