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Seeing Through the Hype?

Can these innovative and emeWhile debate persists about the harmful effects of blue light, one study suggests potential drawbacks of blue light-blocking filters rging interventions for managing myopia guarantee long-term safety and effectiveness?

As the prevalence of digital devices increases, so does the concern about the potential long-term effects of exposure to blue light emitted by screens. With 80% of American adults using digital devices for more than two hours daily, the use of blue light-absorbing filters in glasses has become popular. However, a pilot study from the University of Granada suggests a potential downside, indicating a slight worsening of blue/yellow color discrimination with these filters.

In today’s fast-paced, technology-driven society, many of us use electronic devices for hours every day, ranging from smartphones to tablets and laptops. There is growing concern about the long-term effects of screen exposure from digital devices, as they emit blue light, which could be potentially harmful to the eyes.

According to statistics from the USA-based Vision Council, 80% of American adults use digital devices for more than two hours a day. Additionally, nearly 67% use two or more devices at the same time, with 59% percent experiencing symptoms of digital eye strain.

There are concerns that continuous exposure to blue light over time could damage retinal cells, potentially causing age-related macular degeneration, cataracts, eye cancer, and growths.

Additionally, exposure to blue light before bedtime may disrupt sleep patterns, which could play a role in the development of type 2 diabetes, cardiovascular disease, cancer, and sleep disorders

Blue light filters: From lenses to devices

Due to concerns that blue light is harmful, the use of blue light-blocking filters has gained popularity among eyeglass wearers. However, there is still ongoing debate over whether blue light really poses actual risks.

In 2018, a comprehensive report1 from two European Commission scientific committees focused on the assessment of potential health risks associated with LEDs concluded that “there is no evidence of direct adverse health effects from LEDs emission in normal use (lamps and displays) by the general healthy population.”

They also recommended further research to ascertain the specific impact of LED lights on the circadian system, as “it is not clear if this evening disturbance of the circadian system leads to long-term adverse health effects.”

Blue light-absorbing filters are currently marketed as an additional feature in ophthalmic lenses, contact lenses, intraocular lenses, as well as screen protectors for devices. In some gadgets, users can adjust the intensity and color temperature of the display by dimming the blue LEDs.

Many ophthalmic lens manufacturers currently offer blue light filters. However, some wearers prefer not to use them due to their impact on chromatic discrimination and color perception.

Those particularly affected are professionals who work closely with color in their respective fields, such as graphic designers, photographers, lighting technicians, painters, and tattooists.

Drawbacks of blue light-blocking filters

A pilot study2 carried out by researchers from the University of Granada, Spain, evaluated the impact of long-term use of eight different blue light-blocking filters on color perception. The study spanned more than two weeks and involved a group of 18 normal color vision observers, comparing them with a control group of 10 observers.

The results of the study published in 2022 indicated a trend toward worsening color perception with the filters on. In summary, the study showed a slight deterioration in blue/ yellow color discrimination with the filters in use.

Co-author Dr. Eva M. Valero highlighted that the study’s findings could raise awareness among optometrists and users. “Using the blue light-blocking filters can have certain consequences in the patient’s color vision, and it could potentially be disturbing for patients that need a fine-tuned color sensitivity for their jobs,” she explained

She added that, currently, there are no studies on human subjects that prove that blue light is actually harmful.

“The implications for patient visual care go beyond the findings of the study. We intend to encourage optometrists to question the use of these blue light-blocking filters for everyone. These filters might have undesirable effects in some cases, and professionals in visual health should be aware of this issue. I would not say that they enhance the visual experience for adults in any way,” Dr. Valero added

“It is our opinion, as a group of researchers in color vision, that these filters have more disadvantages than benefits. The alleged harmful effects of the blue portion of visible light have been questioned in many scientific studies. And, indeed, there is a current of thought that suggests blue light is not harmful at the levels we are exposed to daily from either natural or artificial sources,” she continued.

“Even if these filters are called ‘blue-blocking,’ we have measured their transmittance functions and found that, at the minimum transmittance, they still let more than half of the incident radiation pass through. So they are not totally blocking the blue portion of the spectrum,” she further explained.

Optimizing eye health in the digital era

On the other hand, Mr. Ryan Ho, an optometrist at Malaya Optical in Malaysia, shared that blue light can potentially disrupt sleep cycles and cause digital eye strain.

“While it is not definitively proven that blue light from screens causes harm to our eyes, the sheer amount of time we spend in front of screens in our daily lives calls for a cautious approach,” he said. “Advocating for the use of blue-light blocking lenses seems like a sensible supplementary measure,” he remarked.

It complements other established practices, such as managing screen time and adhering to the ’20-20-20 rule,’ which recommends taking a 20-second break to look at an object 20 feet away every 20 minutes

The study achieved an average axial length adjustment of approximately 1.217 mm in rabbit eyes, potentially translating to a significant myopia correction in humans (~2.5 diopters).

“This dual approach—using blue light-blocking lenses in conjunction with mindful digital habits—fits well with our modern lifestyle. It’s about striking a balance that offers extra comfort and protection in a world where screen usage is increasingly prevalent,” advised Mr. Ho.

References

  1. European Commission. Scientific Committee on Health, Environmental and Emerging Risks SCHEER. Opinion on Potential risks to human health of Light Emitting Diodes (LEDs). Available at https://health.ec.europa.eu/system/files/2019-02/scheer_o_011_0.pdf. Accessed on December 22, 2023.
  2. Santandreu M, Valero EM, Gómez-Robledo L, et al. Long-term effects of blue-blocking spectacle lenses on color perception. Opt Express. 2022;30(11):19757-19770.

Editor’s Note: This article was published in COOKIE Magazine Issue 15.

Ryan Ho_resize

Mr. Ryan Ho

first undertook a Bachelor of Science in Microbiological Sciences at the University of Kansas, USA, in 1996 before studying Optometry at the International University College of Technology Twintech, Malaysia, in 2008. He is a skilled optometrist with over 15 years of experience. He obtained his first degree in B.Sc. at the University of Kansas, USA, and continued to pursue his passion for his Bachelor of Optometry (Hons) in Malaysia. His opinions on the treatment of Ortho-k, monovision, progressive lens fitting, and myopia in children have been well sought after on national television stations, such as RTM, TV3, and national newswires, as well as publications such as Bernama, The Star, and more. He has helped build Malaya Optical from a family-owned business of three generations to become a two-time award winner of the prestigious Brand Laureate Award. While he is busy running his retail practices, online store, and building an eyewear brand, Mr. Ho makes sure to spend quality time with his family as they are the inspiration behind this brand. During his leisure time, Mr. Ho enjoys riding his road bike on numerous road adventures.

ryan@malayaoptical.com

Eva Valero Benito

Dr. Eva M. Valero

obtained a Bachelor’s Degree in Physics in 1995 and a Ph.D. in 2000, both at the University of Granada. She worked as an assistant professor at the Department of Optics from 2001 to 2007 and later as an associate professor from 2007 onwards. Dr. Valero is an active member of the Color Imaging Lab at the University of Granada. Initially focusing on spatial color vision, her research interests have expanded to include multispectral imaging and color image processing, with a specific focus on Color Vision Deficiency Aids.

valerob@ugr.es

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