There are two things to worry about - oil level and oil pressure.
If the level in the sump is too low, then two things happen. Firstly, there is a less oil, so that the remaining oil has to work harder and will be hotter. Secondly, there is a chance that under cornering load, all of oil may move sideways and allow the oil pump to suck air .... which kills the oil pressure.
Oil pressure is what keeps the bearings apart - well it doesn't actually separate them (there is some complex physics around this), but you have to keep shoving oil into the bearings to allow the physics to work. If no oil goes in, then the bearings touch, and they wear very fast indeed (pretty much instantly).
So - if you had enough oil in the sump to ensure coverage, you will have done no damage. If you saw the light flickering on hard cornering, then your engine will have aged considerably....