This happened yesterday. I didn't hear anything hit the screen on the journey and it wasn't there at the start. There doesn't appear to be any impact damage.
I cant see how this can be repairable - but any windscreen experts tell me if it can be injected, my suspicion is not...
years ago i had a belter of a bullseye injected and you couldnt see it afterwards. guy doing the repair told me the secret was to wave a fag lighter below the glass to draw in the resin . it was far worse than what you have
long as yours isnt a Porsche! the windscreen guy told me he found out the hard way that porsche has a layer of plastic on the Inside of the screen - you can imagine what happened when he waved a fag lighter onto that one