My ops manual says the following (EU-ops):
Flight below Minimum Sector Altitude (MSA) A flight shall not be conducted below MSA unless:
• Under radar vectors at or above Minimum Radar Altitude; or
• On a promulgated route or instrument approach procedure; or
• In continuous visual contact with the ground and able to ensure adequate clearance from all obstacles affecting the intended flight path.
So no requirement to see the runway.
On a circling approach you are requiered to see the aerodrome environment, not the runway until making the final descent.
On top of that guys, on VFR flights most of the time you don't see a runway either. Is that dangerous?