Or half open. Or half closed. What do you do?
If its closed it can get too hot. Sometimes its like riding through a Batman movie, Whack, Splat, Bang on the visor. If I open it I'm bound to have an eye gouged out. Then there's the occasional bug that flies in between the helmet and my head, as I can feel it wriggling there, really annoying. So I have to stop, take the helmet off inspect it and ruffle my hair to try and get rid of it - whatever it was. In cold weather it fogs up (haven't tried a Pinlock insert yet) so I have no choice but to open it. I find the air vents on the helmet are not helpful. And if I keep it ajar it gets noisy, but at least the visor clears up.