Hey man wats up!
I had the same issue with my eye exam in Ireland... our system using x/4.5 while they use 5 or 10...
My specialist scribbled out their " /10" and did it based on " /4.5" same exam you ust have to do a little math to convert to " /10"
Either way
I would go back to him and ask him to do it "as he would do it" and write it on the form... I presume eurocontrol get this all the time and there was no issue with my eye exam submission. Dont submit it with any blank spaces...
I hope this helps!