Musk cloud - blind keep wearing off?

[Skunkupine]

It seems that when using Musk Cloud, the blindness wears off every turn, even though the cloud persists. The blind text is shown every turn, but at the end of every turn it wears off and the blind icon does not show.
Is that a bug, or behavior as designed?

 

[Theron]

I'm pretty sure it's just a side-effect of the way it's implemented. Debris Field behaves the same way.