In general, does the caster of a visual illusion experience the full effect of that illusion? For example, Minor Illusion can create an un-moving illusory object that seemingly everyone can see. Would this object be as opaque for the caster, or more faint, as it would appear to someone who successfully investigated the illusion?
For example, if an illusionist created the appearance of a brick wall between himself and some attackers, would the illusionist still be able to see the attackers? Or would the illusionist have to use an action to Investigate his own illusion first?