Ó Dalláin
Ó DALLÁIN—I—O Dullane, O Dallan, O Dallon, Dallon, Delane, (Delany), &c.; 'descendant of Dallán' (diminutive of dall, blind); formerly a not uncommon surname throughout the south of Ireland; now also in use in West Connacht, where it is incorrectly anglicised Delany. See Ó Duilleáin, which is a variant.
Alphabetical Index to Irish Surnames