When fighting shifter forms (sand lizard in this case) you can use 'nerve' against them typically, makes sense as they have nerves and pressure points like any other animal including fish.

When you blindness dust or they are blinded for any reason however they no longer have nerves/legs/feet etc.

So the bug is blindness gives them the same restrictions you gave water forms when typically 'nerve' works as it was designed to.

Could you throw up a log if you have it please?