Required Resources
Read/review the following resources for this activity:

• Textbook: Chapter 14
• Lesson 1, 2
• Link (library article): Myopia and Ambient Lighting at Night (Links to an external site.)
• Link (library article): Myopia and Ambient Night-Time Lighting (Links to an external site.)
• Link (website): What Are Clinical Trials and Studies? (Links to an external site.)
• Minimum of 1 scholarly source (in addition to the textbook and noted readings)

Introduction
As the text points out, causal reasoning is used in clinical studies. As a professional in the health field, you will undoubtedly be referring to cause/effect studies for the rest of your professional life. In this discussion, you are asked to expand and deepen your understanding of clinical studies.

In 1999, a study on the causes of myopia appeared in the prestigious journal Nature (Quinn). The study received wide-spread publicity in leading newspapers, such as the New York Times, and on television outlets, such as CBS and CNN. Within a year, another article in Nature followed up the 1999 study (Zadnik et al., 2000). The studies had dramatically different findings.

Initial Post Instructions
Using what you have learned from the text, 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>.

Follow-Up Post Instructions
Respond to at least two peers or one peer and the instructor. Further the dialogue by providing more information and clarification.

Writing Requirements

• Minimum of 3 posts (1 initial & 2 follow-up)
• Minimum of 2 sources cited (assigned readings/online lessons and an outside source)
• APA format for in-text citations and list of references