I found the following sentence in Google Online Dictionary:
a landscape in which inner and outer vision were reconciled
But it's kind of difficult for me to tell whether vision is countable or not. On one hand, vision seems to be uncountable, so even pairing it with the logical connector and won't make it plural. So, vision should be used instead of *visions. However, in this case was should be used instead of were. On the other hand, if it's countable then visions is the choice and not vision.
Could someone shed some lights on it?