The goal of this project was to explore how different types of vocabulary exposure shape the connections formed in the L2 lexicon and how these, in turn, affect L2 language processing. During L2 acquisition, words are often presented in thematic lists (e.g., food), favoring a lexicon organized by shared features (burger-hot dog). However, thematic lists offer only a partial picture of how words interconnect. For example, beer and football do not share any features and do not belong strictly to the same theme (food and sports, respectively); still, they co-occur frequently and are associated in the lexicon. A multisession training study and visual world eye-tracking tests were conducted to assess how different types of vocabulary exposure impact L2 processing. Intermediate L2 Spanish learners were trained under one of two conditions, thematic lists (TL, as in textbooks) or words presented in visual scenes (VS) with vocabulary related by co-occurrence. The VS group showed significant changes in their gaze patterns, resembling the naturalistic exposure baseline group (native speakers), more than the TL group. The results are interpreted in light of the anticipatory processing literature and the strength of representations as a result of naturalistic vs. formal exposure to L2 vocabulary.