It’s a normal and almost unavoidable part of life these days that we spend a significant amount of time looking at screens on digital devices. Whether for work, online shopping, watching your favourite streaming service or time spent on social media, most of us are exposed to screens daily. The impact of this consistent screen time on our eye health should not be underestimated, especially the long-term impact on vision for children and young adults.
Screens from digital devices all emit blue light, a short wavelength high energy light that forms part of the visible (to the human eye) light spectrum. Sunlight is the largest source of regular exposure to blue light. The benefits of natural blue light from sunlight exposure include improved mood, cognition, and memory, and it is essential for developing children’s eyes and vision. However, in the absence of sunlight, day and night, we are surrounded by artificial blue light sources from computer screens, tablets, smartphones, LED TVs, car headlights, LED lights and fluorescent lighting.
What’s the problem with blue light?
Due to the high-energy nature of blue light, it can penetrate the back of the eye through its normal protective filters. The blue light can then reach the retina and macular located at the back of the eye, which both have crucial roles in allowing normal, healthy vision. This continued exposure to blue light can lead to oxidative stress and increased free radicals, which may cause damage to the cells in the eyes, including the macular. This is of particular concern in young children as the pigments and protective filters in the eyes are still developing.
In addition to the blue light exposure, constant and up-close focus on screens can lead to eye strain and fatigue, contributing to a progressive decline in visual function longer term. Every blink of the eye provides moisture and oxygenation to the eyes and removes debris. The constant focus on screens means we are less likely to blink, increasing the risk of developing dry eyes, redness, and irritation.
Another significant impact of constant blue light exposure is that it suppresses the body’s production of the sleep hormone melatonin, impacting our natural circadian rhythm and, therefore, our sleep patterns. Lack of good-quality sleep has been linked to numerous chronic health conditions, including heart disease, diabetes, obesity and depression.
So, what can you do to protect your eye health?
1. The protective power of carotenoids
Carotenoids are pigments found in plants, algae and some bacteria and fungi. They are abundantly found in brightly coloured yellow, orange and red fruit, vegetables and flowers. Carotenoids act as a natural ‘sunscreen’ for plants, absorbing excess light energy and acting as powerful antioxidants protecting from damaging UV radiation.
Lutein and Zeaxanthin are two specific types of carotenoids that have been shown to play a protective role in the macula and lens of the eye. They form a yellow pigment in the macula, which exerts a natural filter or internal ‘sunglasses’ effect against harmful blue light reaching the retina. These carotenoids provide nutritional support for the macula region of the eye and protect against free radical damage.
The body cannot synthesise Lutein and Zeaxanthin, so they must be derived from a dietary or nutritional supplement source.
2. Dietary sources of Lutein and Zeaxanthin
Dietary sources of Lutein and Zeaxanthin include egg yolk, corn, kiwi fruit, grapes, orange capsicum, orange juice, zucchini, and squash. Lutein is found in the highest amounts in corn, whilst Zeaxanthin’s primary source is orange and yellow capsicum.
3. Supplements for eye health
If you don’t feel like getting enough lutein and zeaxanthin from dietary sources, consuming a supplement to support eye health may be beneficial. The age-related eye diseases study (AREDS) conducted by the Vision Eye Institute in the US concluded that 10 mg of lutein and 2 mg of zeaxanthin effectively reduced the progression to advanced age-related macular degeneration. The AREDS formulation used in the studies also includes other nutrients commonly found in eye supplements, such as beta-carotene, vitamin C, vitamin E, copper, and zinc, which have an antioxidant effect and support general eye health.
Beneficial herbs for eye health include African Marigold (a natural source of lutein) and Bilberry, which are high in protective antioxidants.
4. Lifestyle tips for protecting your eyes
- Protect your eyes from the sun by wearing sunglasses.
- Try and limit your digital device use, particularly 1-2 hours before bed. This will enable your body to produce the melatonin required for healthy sleep patterns.
- Follow the Australian national guidelines for screentime for children:
a) No screen time for children younger than two years
b) No more than one hour per day for children aged 2–5 years.
c) No more than two hours of sedentary recreational screen time per day for children and young people aged 5 –17 years (not including schoolwork).
- Give your eyes a break and follow the 20-20-20 rule – every 20 minutes, stare at something 20 feet (6 metres) away for at least 20 seconds. This activates your distance vision allowing your eyes to ‘reset’. Don’t forget to blink more often to keep the eye moist and reduce redness and irritation.
As with most health conditions, prevention is critical to protecting your eye health long term. Make sure you have regular check-ups at your optometrist, eat a carotenoid-rich diet and consider ways to reduce your exposure to blue light daily.
