The night vision devices tend to operate only in the requirement of the little amount of light but, the infrared devices does not use any visible light spectrum to operate over the bandwidth.
The infrared helps to detect the heat radiated from the targeted object whereas, the night vision helps to detect the visible light condition. The night vision works based on the lower amount of light whereas, the infrared does not work on any kind of lighting.
The infrared devices are better to target an object than the night vision devices. The night vision devices suffer in amplifying the image with the light source whereas, the infrared device do not get affected by this amplification problem. The night vision constitutes the ability to counteract by the bright light source whereas the infrared constitutes the ability to counteract the cooling effect.