thanks for all the tips guys.
In the mean time......
blocking up the visor vent and removing the mouth guard has had a good effect.
The wind is now direct straight at my top lip and nose. There is no longer a direct blast into my eyes, although there is still air flow around my face.
I think this will do me until I get a new helmet, which I intend to purchase over the next month or so.
...
I cannot recall seeing a SPARX this side before