Three articles:
1)Myopia and Ambient lighting at Night
2)Myopia and Ambient Night-Time
3)What are Clinical Trials and Studies
Using what is in the text of the articles, as well as any other sources you may find useful (including the website in the Required Resources), analyze and evaluate the methodology of both studies and how methodology affected the differences in how the studies were reported.
Reportage of both studies can be found with an Internet search using all of the following terms: <Philadelphia myopia night lights>.