How red and infrared light protect the retina from blue light

Introduction – why this study was created

Today’s digital age exposes us extremely to blue light (e.g., from screens), which in high doses can damage photoreceptors – cells in the retina sensitive to light. Previous research promises protection thanks to red (670 nm) or near-infrared (810 nm) light, but the effects have so far lacked a detailed molecular explanation.  .

What exactly did the study do

• Used primary mouse retinal cells, first damaging them with strong blue light (BL).

• • The analysis was carried out within a few hours and in detail:

    1. early changes (oxide stress),

    2. late processes (mitochondrial function, apoptosis, gene activity).

       The damage was then "treated" either with 10 minutes of red (RL, 670 nm) or infrared (NIRL, 810 nm) light.

        

Main findings

1. Not only complex IV, but also complexes I and II: Previous theories considered complex IV (cytochrome c oxidase) as the main target – however, studies have shown that both red and NIR light also activate complexes I and II, thereby improving mitochondrial respiration and ATP production  .

2. Reduced oxidative stress and cell preservation: Damaged cells exhibited significantly lower oxidative stress and fewer signs of mitochondrial apoptosis (e.g., lower activity of Bax, Caspase-9)  .

3. Genetic response – α-crystallins: The study found increased expression of α-crystallins, proteins with a protective function – suggesting the restoration of the protective environment at the mitochondrial level  .

Why is it important

• Expands our understanding: not only complex IV, but also other smaller respiratory complexes are key to the PBM (photobiomodulation) effect.

• Supports the therapeutic potential of red & infrared light – the foundation for future therapies against degenerative retinal diseases.

What next?

• The study was conducted in vitro (in laboratory conditions with mouse cells). The next step is in vivo tests and clinical trials in humans.

• It is necessary to verify the appropriate dosage, frequency of exposure, and safety for long-term use.

In conclusion

This study provides strong evidence that red (670 nm) and near-infrared (810 nm) light activate mitochondrial respiratory complexes I, II, and IV, significantly reducing photoreceptor damage caused by blue light. This discovery paves the way for modern, non-toxic methods of vision protection—whether in preventing digital eye strain or in treating degenerative retinal diseases.

link to the study: https://pmc.ncbi.nlm.nih.gov/articles/PMC7177783/