Eye Health and Using Red Light Therapy to Improve Vision
Out of all the five senses, we as humans are primarily visual communicators and use eyesight as our dominant sense. The eyes are one of the most energetically demanding systems in the body, containing the highest mitochondrial density amongst all organs [1]. In this article, we take a deeper look at eye health and how exposure to red light may help improve mitochondrial function in retinal photoreceptor cells.
Overview of How Eyes Work
When it comes to our eyes, most of us have heard of the retina. This light-sensitive layer of tissue is located at the back of the eye and holds our photoreceptor cells called rods and cones. These specialized cells are how we process light. Rod cells require lower energy to activate and are responsible for our vision at night when light levels are low. Cone cells are the opposite, requiring larger amounts of energy to activate and are primarily responsible for our vision during the day [2].
In today’s world, it’s not uncommon to overuse our cone cells to maintain good vision. This is primarily a result of increased artificial lighting in the environment. We now have full control over how much light we are exposed to, allowing us to fully light our homes or workplace at any given time of the day. This imbalance causes the cone cells to do the majority of the work for our vision, and doesn’t allow the rod cells to take over when they would naturally do so in the evening.
Remember, rod cells require “low levels” of light to activate or they stay turned off. As we age, an imbalance in photoreceptor cells can occur when the rod cells begin to die off, allowing the cone cells to become our dominant source of vision. Cone cells, unlike rod cells, do not die off, but instead function at a reduced capacity, which is why we start to see a decline in vision. This process is thought to be a decrease in mitochondrial function, which ultimately leads to a decrease in cell energy. Cone cells are known to hit an aging threshold at around 40 years, which is when a decline in vision commonly occurs [3]. This is why it is important to support our cells as we age, in order for us to maintain strong, healthy vision.
Red Light Supports Aging Vision
In a 2021 study, researchers investigated using red light to improve color vision in aged individuals. Improvements to color contrast is significant to vision, as it allows us to see colors more clearly. A group of healthy men and women ranging from 34 to 70 years in age, were treated using red light only at approximately 670 nm. Participants who were exposed to a single three minute red light treatment were later evaluated for improvements in color vision. It was discovered color contrast thresholds improved by up to 20 percent in participants greater than 35 years in age. Improvements lasted as long as a week after the single treatment. It was also determined that younger participants who did not experience improvements were the result of still having good cell function in their photoreceptor cells [4].
Results from the study are seen to be positive, prompting the need for additional research to understand the full capability of using red light exposure to slow down the aging process of photoreceptor cells.
Joovv Eyewear Guidelines
While not necessary with our previous generations of devices, you may be curious why Joovv requires the use of eyewear for our newest generation when exposing the eyes to red light could be beneficial. That's a great question and one we are happy to help answer. Joovv only requires eyewear when treating with a setting that utilizes near infrared light. Visible light wavelengths below 700 nm have less of an impact on increasing tissue temperature, which can be harmful for cells. With our eyes containing some of the most sensitive tissues in the body, exposure to energy sources that increase tissue temperature should be treated with caution. Learn more about our protective eyewear guidelines here.
As part of Joovv’s commitment to safety as a medical device, all of our devices have been evaluated following IEC 62471; Photobiological safety of lamps and lamp systems. This is a safety standard recognized world wide when determining the risk levels of a device for human use. For more information on device safety, check out this article.
Conclusion: Red Light Can Support Eye Health
The use of red light on the eyes can be beneficial in restoring cell function, especially as we age. Joovv recommends using the provided eye protection for our latest generation 3.0 and Go 2.0 devices when treating in a setting that utilizes near infrared light. When utilizing the red wavelength only, eye protection is not required, and may be beneficial for maintaining healthy cellular function in the retinal layer. And as always, if you have any questions or concerns, we recommend consulting with your trusted healthcare provider.
Sources:
[1] CJ Kazilek, Kim Cooper. "Rods and Cones". ASU - Ask A Biologist. 06 Jan 2010. ASU - Ask A Biologist, Web. 10 Oct 2022. https://askabiologist.asu.edu/rods-and-cones.
[2] Harpreet Shinhmar, MSc, Manjot Grewal, BSc, Sobha Sivaprasad, MBBS, PhD, Chris Hogg, Victor Chong, MBBS, PhD, Magella Neveu, PhD, Glen Jeffery, DPhil, Optically Improved Mitochondrial Function Redeems Aged Human Visual Decline, The Journals of Gerontology: Series A, Volume 75, Issue 9, September 2020, Pages e49–e52, https://doi.org/10.1093/gerona/glaa155
[3] Shinhmar, H., Hogg, C., Neveu, M. et al. Weeklong improved colour contrasts sensitivity after single 670 nm exposures associated with enhanced mitochondrial function. Sci Rep11, 22872 (2021). https://doi.org/10.1038/s41598-021-02311-1
[4] Despoina Gkotsi, Rana Begum, Thomas Salt, Gerassimos Lascaratos, Chris Hogg, Kai-Yin Chau, Anthony H.V. Schapira, Glen Jeffery. Recharging mitochondrial batteries in old eyes. Near infra-red increases ATP. Experimental Eye Research. Volume 122, 2014, Pages 50-53, ISSN 0014-4835. https://doi.org/10.1016/j.exer.2014.02.023.
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