Is too much screen time causing ‘digital dementia’? What is ‘20-20-20’ rule to protect your eyes?

For many, daily life is deeply tied to the online world: working, cooking, shopping and walking while listening to podcasts, reading news online each morning, searching for recipes, discovering new books, and downloading favourite radio shows. But that reliance may come with risks.

Concerns have grown after a report on 60 Minutes Australia titled “Brain Drain”, which examined children’s screen time and brain health. The findings were striking. Research suggests that young people who spend long hours on screens - gaming, watching YouTube or scrolling through Instagram - and do little physical activity can show brain changes similar to those seen in older adults with Alzheimer’s disease.

“Preschoolers and kids who use devices regularly have abnormal development of their white matter tracks,” he said.

These fibres connect different parts of the brain and are vital for healthy communication between regions. Williams warns that too much time online could be linked to a rise in early-onset cognitive problems, even among people aged 25 to 35.

He points to a sharp increase - about 400 per cent - in young adults seeking help for such issues. The youngest case he highlights is a 19-year-old whose cognitive decline, driven by extreme screen use, resembles brain scans of much older patients.

However, the picture is not entirely negative. Evidence suggests that internet use may benefit older adults.

A large US study by New York University’s School of Global Public Health followed around 18,000 adults aged 50 to 65 over eight years. Published in the Journal of the American Geriatrics Society, it found that regular internet users had roughly half the risk of developing dementia compared with non-users.

Researchers say the effect is “dose-dependent”, forming a U-shaped curve. Both no use and excessive use were linked to higher risk, while moderate, purposeful use appeared beneficial.

Experts quoted by SCMPS part of the benefit comes from staying engaged with modern life, from online banking and booking travel to keeping in touch with family through video calls.

The key, however, lies in how the internet is used.

Mindless scrolling offers little cognitive benefit, while tasks such as emailing, budgeting or researching information can help keep the brain active. Even online games vary in value; to build “cognitive reserve”, they must be challenging rather than repetitive.

The so-called “brain rot” seen in some young people, experts warn, stems from passive consumption rather than active thinking.

Healthier use involves treating the internet as a tool — for learning, connection and daily tasks — rather than a constant background habit.

Guidance from the Washington-based Information Technology and Innovation Foundation suggests going online with a clear purpose and limiting use to a couple of hours a day. Activities that involve memory, planning and social interaction — such as video calls or language learning — are particularly beneficial.

Experts also advise limiting passive social media use to 20 to 30 minutes, turning off notifications, and disconnecting from devices at least 30 minutes before bedtime to protect sleep.

Physical health matters too. The American Optometric Association recommends the 20-20-20 rule — every 20 minutes, look at something 20 feet away for 20 seconds — along with regular movement to reduce the effects of sitting for long periods.

Curating social media feeds can also help. Unfollowing upsetting content and choosing more positive or informative accounts may support mental well-being. Taking regular breaks from screens altogether is encouraged.

Offline activities remain essential. Hobbies such as walking, hiking or gardening provide real-world engagement that supports mental health, with research highlighting their benefits.

Warning signs of excessive use include feeling empty after browsing, staying online longer than intended, or neglecting relationships and exercise.

For regular users, the aim is balance. Using the internet as a practical tool can support brain health, but overuse — or complete avoidance — may carry risks.

The challenge, experts say, is to find that “sweet spot” in between.