Understanding comprehensive income, comprehensively

FOR the last six years or so, corporate financial statements have sported a new disclosure in the form of "comprehensive income" and "other comprehensive income". The change was introduced to improve the level of transparency in financial statements; and investors here are no doubt used to seeing these entries by now.

But how many understand what comprehensive income consists of, how it is different from traditional reporting of net income and how its introduction has changed the nature of financial statements here? In other words (if you'll permit me to be glib), how comprehensively do investors understand comprehensive income?

Based on anecdotal evidence, it appears to be less than comprehensive; and that's not just the case with investors but even with some companies and other stakeholders as well.