How can we help children protect themselves from blue light? Support from Vision Kids!

Between LED lighting and digital screens, our children are increasingly exposed to blue light. Concerns about its possible effects on their health are growing: both the retina and circadian rhythms may be at risk. But how can we protect them? Filtering screens and lenses seem to offer little benefit, while increasing the intake of nutrients that make up the eye’s natural defenses has proven to be a more promising strategy.

The use of LED lights has gradually increased from the 1990s to today, driven by a necessary focus on the economic and environmental costs of indoor lighting. As a result, our exposure to blue light—which LEDs emit in large amounts—has increased.

The widespread use of digital devices such as computers, tablets, and smartphones has contributed as well; the backlighting systems of their screens rely precisely on LEDs.

Considering that today we spend more than 90% of our time indoors, often in front of these types of screens or exposed to artificial lighting, the question arises naturally: does increased exposure to blue light affect our eyes and overall health?

Indeed, the use of digital screens has been linked to undesirable effects on vision. Blue light, for its part, triggers reactions in most ocular tissues, particularly the cornea, the lens, and the retina.

Depending on the type of blue light exposure, temporary or permanent damage may occur, and even if the immediate consequences seem insignificant, experts are concerned about long-term effects—especially for children, who will likely spend a greater portion of their lives exposed to high levels of blue light.

Moreover, although the concern centers around blue light from artificial sources, it is important to remember that this light is present everywhere in our environment and also comes from the Sun, the Moon, and flames.

The intensity of natural blue light varies throughout the day—highest at midday and lower at dawn and dusk—and is influenced by latitude, altitude, weather, and season.

The human body has evolved to use changes in the intensity of this light to regulate circadian rhythms, meaning functions that must stay synchronized with the cycle of day and night, such as sleep-wake patterns. Therefore, it is reasonable to wonder whether increased exposure to blue light may also influence these rhythms.

Let’s explore the potential risks associated with increased blue light exposure and how to reduce them, focusing especially on the eye structure that appears most at risk: the retina.

What the retina is and how it works

The retina is a structure made up of ten layers containing cells capable of detecting and interpreting visible light (400–700 nm).

In its innermost part lie the nerve fibers of the optic nerve, which transmit the signals captured by the retina to the brain and distribute them to different brain areas.

The outermost part (the retinal pigment epithelium) is essential for supplying nutrients required for the proper functioning of the two main visual structures: cones and rods. It is also crucial for retinal development, for counteracting oxidative stress generated by light exposure, and for several other processes vital for healthy eye function.

Cones and rods detect light, but they are not the only light-sensitive cells in the retina. Deeper within are the intrinsically photosensitive retinal ganglion cells (ipRGCs), which contain melanopsin, a pigment that primarily absorbs blue light.

Stimulation of ipRGCs by blue light plays an important role in light responses not related to image formation. Thus, blue light is involved both in vision and in other physiological processes triggered by light exposure.

What blue light is and how it affects the eyes

So what exactly is blue light? It is the highest-energy electromagnetic radiation within the visible spectrum. It can be divided into two categories: blue-violet light (380–450 nm, also known as “high-energy violet light”) and blue-turquoise light (450–500 nm).

Most research has focused on blue-violet light, but blue-turquoise light can also reach the retina, reducing melatonin levels (a key hormone for regulating sleep) and thus influencing circadian rhythms. Additionally, light stimulates the release of dopamine and serotonin, two neurotransmitters that also affect mood.

Regarding the effects of blue light on ocular structures, shorter wavelengths can alter the eye’s surface, generating oxidative stress and inflammation, and inducing cell death.

In the retina, prolonged blue light exposure increases reactive oxygen species, promotes the formation of deposits and microvascular changes—all associated with age-related vision problems. Photoreceptors decrease, lipids oxidize, and cells die.

Blue light can also damage the lens, especially with aging, causing gradual yellowing and darkening, with increased risk of cataracts.

Studies indicate that even brief exposure to doses considered safe may influence cone and rod function, and blue light may induce toxic effects even at intensities commonly found in households.

Some research has focused on digital screens, identifying chronic damage after exposure to phone screens for more than 8 hours a day over more than 5 years. The damage appears to involve all layers of the retina and seems cumulative and time-dependent.

More recent studies also suggest non-visual effects, such as possible involvement of blue light in triggering migraines.

How to protect yourself from blue light

Today, screen brightness is 100 times lower than potentially harmful levels; however, the main concern is the cumulative effect of long-term exposure.

Therefore, the first way to protect children from potential blue light-related damage is to limit exposure—for example, avoiding LED lights with a high blue component in spaces where they spend long periods. It is better to choose warmer lights instead of cooler ones and reduce screen use before bedtime and during the night to avoid disrupting their circadian rhythms.

The effectiveness of strategies such as blue light–filtering screens and lenses is uncertain: studies have not found significant retinal benefits.

It may instead be useful to strengthen the eye’s natural protection systems, made up of macular pigments (lutein and zeaxanthin), which work in synergy with antioxidants like vitamin C, vitamin E, and zinc to limit oxidative stress generated by blue light.

How to protect children from blue light through diet

Neither lutein nor zeaxanthin can be synthesized by the human body; they must therefore be obtained externally.

These carotenoids are found in fruits and vegetables (especially leafy greens) and can also be consumed through dietary supplements, which help support the naturally abundant lutein and zeaxanthin stores in children’s eyes—stores that tend to decrease with age.

Lutein and zeaxanthin absorb blue light, prevent the formation of reactive oxygen species, and help eliminate them. They also counteract inflammation that worsens light-induced damage and may prevent the abnormal blood vessel growth associated with certain eye diseases.

Their benefits for retinal health are supported by numerous studies, including those on supplementation.

Vitamin C is present in various eye tissues, while vitamin E is especially abundant in retinal cell membranes. Both prevent oxidative stress and protect cell membranes.

Lastly, zinc has recognized antioxidant properties and is particularly abundant in the eye; together with lutein, zeaxanthin, and vitamins C and E, it is considered a key nutrient for protecting the eye from blue light–induced damage.

Thus, the best way to protect children from the side effects of blue light seems to be leveraging the properties of nutrients abundant in the Mediterranean diet and easily obtained through well-formulated dietary supplements.

References:

Antemie RG, Samoilă OC, Clichici SV. Blue Light-Ocular and Systemic Damaging Effects: A Narrative Review. Int J Mol Sci. 2023 Mar 22;24(6):5998. doi: 10.3390/ijms24065998

Cougnard-Gregoire A, Merle BMJ, Aslam T, Seddon JM, Aknin I, Klaver CCW, Garhöfer G, Layana AG, Minnella AM, Silva R, Delcourt C. Blue Light Exposure: Ocular Hazards and Prevention-A Narrative Review. Ophthalmol Ther. 2023 Apr;12(2):755-788. doi: 10.1007/s40123-023-00675-3