"Like a blind person in a dark room."
A simile.
A metaphor
There is not specific collective noun for the noun ignorance. The noun ignorance is an uncountable noun; quantities of ignorance are expressed in degrees, for example, some ignorance, much ignorance, total ignorance, etc. A term that expresses ignorance as a collective would be, 'the collective ignorance of a group' or 'the combined ignorance of a group'.
It is a simile.
As quick as a wink is a simile. ----
simile
simile its a simile when you use "like"
simile It is an example of a simile (uses like or as). A simile in itself though is a type of metaphor.
simile
that man
Simile
It is a similie as you are comparing (something) to how sly the fox is. A similie uses the words "like or "as".