Reading these stories it seems the rationale is "lazy bureaucrats". Clearly where this ends up is putting all poor people into a "system" which ultimate serves the blind will of the faceless bureaucrats running it. The pretext is that this power is used to "help" the poor, but ultimately it will be used simple to keep the faceless people in power--come hell or high-water.Iris scanning refugees is basically akin to iris scanning for food stamps. Truly the banality of evil.

How well do cosmetic contact lenses defend against this?

Start wearing them as a matter of course.