Ignorance is a lack of clarity. It is not something, it is its absence. Just as darkness is the absence of light, so too is ignorance the absence of clarity. And just as a shadow obscures seeing, so too does ignorance obscure understanding. The light we want is the literal light of consciousness.
As I wrote prior, Yoga defines ignorance as seeing self and reality incorrectly. They are shadowed leading to incorrect conclusions about who I am and what the world is.
The light of awareness brings clarity.