What is Full-Spectrum Light Therapy?

Full-spectrum light therapy is designed to mimic the broad range of wavelengths found in natural sunlight. The idea behind this therapy is that exposure to this wide array of wavelengths might help slow down the onset and progression of myopia, especially in children.

What Does Research Say?

Several clinical studies have shown that outdoor sunlight exposure is linked to lower rates of myopia. Increased time outdoors and higher light intensity are consistently associated with a reduced risk of developing myopia in children, as demonstrated in various large-scale studies. This has led researchers to wonder if boosting indoor lighting could have similar effects.

One such study conducted in rural China looked at whether stronger indoor lighting could help control myopia. The results showed that children in classrooms with enhanced lighting systems had a slower progression of myopia compared to those in classrooms with standard lighting. However, the light outdoors is much more intense, and natural sunlight offers a more consistent and uniform light exposure than indoor lighting. This means that while improving indoor lighting might have some benefits, it should be done with caution.

What Are the Challenges?

Although increasing indoor lighting has shown some promise in controlling myopia, more research is needed to understand how factors like the spectral composition (types of light) and light intensity interact to influence eye health. Indoor lighting cannot fully replicate the natural outdoor conditions that are more beneficial for myopia prevention.

Fig 4. Spending more time outdoors may reduce risk of myopia via multiple means. Image from the Paper How does spending time outdoors protect against myopia? A review.

The Future of Light Therapy

Light therapy holds promise as a non-invasive and accessible option for managing myopia. Among the various light therapies, red light therapy has the most substantial evidence supporting its effectiveness, with full-spectrum light therapy also showing potential. Other therapies, like violet and cyan light, contribute to the range of available treatments, although they are still being studied.

As research progresses, it's important for patients and families to stay informed about the latest findings and to discuss any potential treatments with their eye care professionals. Understanding the role of light in eye health can empower us to take proactive steps in preventing and managing myopia, ultimately improving the quality of life for millions of people worldwide.

References

1. He M, Xiang F, Zeng Y, Mai J, Chen Q, Zhang J, et al. Effect of Time Spent Outdoors at School on the Development of Myopia Among Children in China: A Randomized Clinical Trial. JAMA. 2015 Sep 15;314(11):1142. 
2. He X, Sankaridurg P, Wang J, Chen J, Naduvilath T, He M, et al. Time Outdoors in Reducing Myopia. Ophthalmology. 2022 Nov;129(11):1245–54. 
3. Hua W, Jin J, Wu X, Yang J, Jiang X, Gao G, et al. Elevated light levels in schools have a protective effect on myopia. Ophthalmic Physiol Opt. 2015 May;35(3):252–62. 
4. Zaabaar E, Zhang XJ, Zhang Y, Bui CHT, Tang FY, Kam KW, et al. Light exposure therapy for myopia control: a systematic review and Bayesian network meta-analysis. Br J Ophthalmol. 2024 Aug;108(8):1053–9. 
5. Lingham G, Mackey DA, Lucas R, Yazar S. How does spending time outdoors protect against myopia? A review. Br J Ophthalmol. 2020 May;104(5):593–9.