[wrp]

Some current systems already have trouble at night. I would expect vision based systems to have even more trouble. Are there any CV based guidance systems?

[z303]

The first to come to mind is the AGM-65 Maverick in both visible light and IR (https://en.wikipedia.org/wiki/AGM-65_Maverick). Later version of the AIM-9 Sidewinder also have IR imaging seekers (https://en.wikipedia.org/wiki/AIM-9_Sidewinder) as do the AIM-132 ASRAAM (https://en.wikipedia.org/wiki/ASRAAM). I'm sure there are a bunch of others.

[wrp]

Need to clarify here. GP appeared to be asking about computer vision based systems, which would involve object recognition. The traditional vision systems such as you referenced are based on contrast detection.