As with many species of Neotropical birds, important aspects of the life history of Spectacled Tyrannulet are poorly known. Despite being quite common across its range, information on song types and geographic differences are little known. There are potentially additional taxa to be described within this species. Additional data from field observation and song recordings (e.g. clarification of dawn song, descriptions of courtship) as well as museum specimens (e.g., molt timing and sequence) are needed. As this species formerly was included in what now is known as Guatemalan Tyrannulet (Zimmerius vilissimus), many life history details of Spectacled Tyrannulet long were assumed to be similar to that species (and to Mistletoe Tyrannulet Zimmerius parvus), but may in fact be quite different; Spectacled and Guatemalan (and Mistletoe) tyrannulets are quite distantly related within this genus.