What is Myopia?

Myopia is a common refractive error that has reached near-epidemic proportions globally. Characterized by an elongation of the eyeball, myopia can lead to significant visual impairment and is a leading cause of blindness worldwide. In response to this growing public health concern, researchers have explored various environmental factors that may influence myopia progression.

How Can Light Therapy Help?

Light therapy involves exposure to specific wavelengths of light to influence the development and progression of myopia. Research suggests that the amount and quality of light exposed to our eyes can have a significant impact on eye growth and health. In this section we will review the current understanding of how different wavelengths of light, including red, violet, and blue light, impact myopia development and can be utilized in clinical practice.

Different Types of Light Therapies for Myopia Management

There are several types of light therapies that have been studied for myopia control. These include red light, violet light, cyan light, and full-spectrum light therapy. Red light therapy has shown the most promising results, with significant evidence suggesting it can slow down myopia progression. Violet and cyan light therapies are still in the early stages of research, but they show potential in controlling eye growth. Full-spectrum light therapy mimics natural sunlight and has been linked to reduced rates of myopia in children, particularly when they spend more time outdoors. Each of these therapies works in different ways and may be useful in managing myopia in combination with other treatments.

Red Light Therapy: the most effective light for myopia control

Red light therapy, typically involving wavelengths around 650 nm, has been extensively studied for its effects on myopia control. Clinical trials and meta-analyses have consistently shown that red light can significantly slow down the axial length (AL) elongation—a critical marker of myopia progression. The mechanism behind red light's effectiveness is thought to be linked to its ability to penetrate deep into the eye, and possibly influencing biochemical processes involved in eye growth. Red light may enhance mitochondrial efficiency in retinal cells, leading to decreased oxidative stress and improved cellular health. This hypothesis, while promising, underscores the need for further research to fully understand the mechanisms.

Red Light Therapy Devices

Red-light therapy: Several manufacturers offer repeated low-level red light (RLRL) products in this innovative field. However, the light design, user interface, and additional features such as treatment session tracking, parental controls and regulatory approvals can differ. The most commonly used device is Eyerising (Suzhou Xuanjia Optoelectronics Technology, China). It emits a wavelength of 650nm at a laser power of 0.29mW and was used in 16 studies in diverse groups, including children with pre-myopia, non-highly myopia and high myopia. It is designed for at-home use, requiring only 3 minutes of use, twice a day, with at least a 4-hour interval between uses.