When I had the privilege earlier this week of driving a Model X in full sun, I noticed that the visor could be configured at just the right angle so as to block the sun very nicely when it was at an otherwise awkward position in the sky - and the windshield. That the visor was in its folded-up thin mode meant that it was obstructing overall vision in a negligible fashion. I can best describe it as being the vehicular equivalent of placing one's hand and arm in front of one's sun-blinded view. But a lot more effective and less tiring. If this explanation is not clear, perhaps Roamer can offer his own attempt at a description, as he was in the car with me.