I don’t think it is truly possible to lack an opinion. Indifference is the opposite of caring, and therefore the opposite of both love and hate at the same time. Indifference is an acceptable state of mind, but it is still an opinion. I will postulate, as silly as it is in extreme abstraction, that the opposite of opinion is only possible in death. Existence itself implies a state of awareness and opinion on abstracted levels of consciousness.
Ignorance is basically lazy indifference