Reducing myopia in children: Experimental design and research ethics practice

[sue_frantz]

“In the U.S., 42% of people are now myopic [nearsighted] – up from 25% back in the 1970s. In some East Asian countries, as many as 90% of people are myopic by the time they're young adults” (Godoy, 2024). That’s a lot of people who need corrective lenses. But the news is worse than that. “Once a kid gets myopia, their eyeball will keep stretching and the condition will get progressively worse. If they develop high myopia, it can increase the risk of serious eye problems down the road, such as retinal detachments, glaucoma and cataracts. It can even lead to blindness” (Godoy, 2024). That, I did not know.

I also did not know “that light stimulates the eye to release the neurotransmitter dopamine, which can slow the eyeball from stretching” (Godoy, 2024). Researchers thought this would make for a good correlational study. In a study of 4,000 children, researchers found that the more time the children spent outside, the lower levels of myopia they had, even after “adjusting for near work, parental myopia, and ethnicity” (Rose et al., 2008).

Here's an opportunity to give your students some experimental design practice in the sensation and perception chapter.

After sharing the above information with students, give small groups this hypothesis:

If children spend at least two hours a day outdoors, they will develop less myopia (nearsightedness).

Ask students to address the following:

1. Design an experiment that will test the hypothesis. Identify your independent variable, including the experimental group and the control group. Identify your dependent variable. All variables should include operational definitions.
2. Your experiment should include random assignment to conditions. Briefly explain the importance of random assignment.
3. Review the five general principles from the Ethical Principles of Psychologists and Code of Conduct of the American Psychological Associatio... By these standards, would it be ethical to conduct your study? Why or why not?

Invite a spokesperson from each group to share their group’s research design and their assessment of the ethics of conducting that study.

To conclude this activity, share this information with your students. A Taiwanese ophthalmologist, Pei-Chang Wu, whose son was entering first grade convinced his son’s school to allow the children to spend more time outside. At the same time, he convinced another school to allow him to test their school children for myopia. “A year later, his son's school had half as many new myopia cases as the other school” (Godoy, 2024).  After these preliminary results, Wu did similar studies at other schools and found similar results.

Pause here to ask your students to assess whether Wu’s research meets American Psychological Association’s ethical guidelines. Why or why not.

Wu obviously has some pretty mean persuasive skills, but check out what he did next. With the data in hand, he convinced Taiwan’s Minister of Education to make a policy change that required schools to get children outside for two hours a day. “The program launched in September 2010. And after decades of trending upward, the rate of myopia among Taiwan's elementary school students began falling – from an all-time high of 50% in 2011 down to 45.1% by 2015” (Godoy, 2024).

If time allows, ask students what schools and parents can do to help ensure children are getting two hours outside each day per the recommendation of ophthalmologists. Are your students ready to start a letter-writing campaign to their local school boards?

References

Godoy, M. (2024, May 13). Want to protect your kids’ eyes from myopia? Get them to play outside. NPR. https://www.npr.org/sections/health-shots/2024/05/13/1250555639/kids-eyesight-myopia-near-sighted-ne...

Rose, K. A., Morgan, I. G., Ip, J., Kifley, A., Huynh, S., Smith, W., & Mitchell, P. (2008). Outdoor activity reduces the prevalence of myopia in children. Ophthalmology, 115(8), 1279–1285. https://doi.org/10.1016/j.ophtha.2007.12.019