I must admit, that I'm not sure about all usual ways, IR-blocking filters are provided for CMOS cameras.
But generally, you can expect this:
A color camera need an IR blocking filter, otherwise the color calibration would be poor with varying light
sources, particularly daylight (low IR content) versus incandescent lamps (high IR content).
The lenses itself have no considerable IR blocking. But it may be the case, that some camera modules
have it internally. In the said internet publications, the IR blocking filter is described as a thin window.