Blind users expect their screen reader to automatically read simple dialog boxes (such as those generated by JOptionPane). The idiom for indicating that these dialog boxes should be read is that their AccessibleRole is 'ALERT'. All JoptionPane dialog that aren't soliciting user feedback in the form of entering text or choosing from a combo-box (e.g. those that simply impart information and the user then presses one [of potentially several] JButtons) should bear the Accessible role 'ALERT'.