After a couple of decades where the numbers of smart devices have increased and the smartphone or tablet is a ubiquitous item of homeware (at least in high income countries),an appropriate question to ask is whether the widespread use of these items have had any biological impact?
The answer could be ‘yes’, at least based on an assessment undertaken by Lancet Digital Health suggests that digital smart devices could well be a contributing factor. Globally, the prevalence of myopia is growing, and it is estimated that half of the world’s population will have developed myopia by 2050.
This trend has also been accompanied by a reduction in the age of onset, an acceleration in the rate of progression, and an increase in the severity of myopia.
A similar review appear with data compiled by the American Optometric Association (“With Childhood Myopia Rates on the Rise, the American Optometric Association Highlights the Importance of Early Intervention through Annual Eye Exams”). This finds that at least 40 percent of U.S. citizens are myopic, or near-sighted.
Both of these assessments are meta-studies, which are reviews of various other items of research where scientists attempt to identify common trends. The Lancet study categorized the range of studies into three different groups. These were:
- Studies that examined smartphone usage exclusively.
- Studies that investigated smartphone and computer usage together.
- Studies that examined smartphone usage with non-digital, near-vision tasks.
The assessment found that close to 50 percent of group 1 and group 2 studies indicated an increased risk of myopia with usage of smart devices and computers, according to a review of the data by Laboratory Roots.
The results may not be totally conclusive due to variations in methodology. For example, some studies neglected to provide details of the screen time or were based on self-reporting (generally self-reporting is an under-estimation of the amount of time people spend connected to their devices).
There are also different ways to measure myopia and it in some studies the medical assessment was based on self-diagnosis.
Nonetheless, the data compiled flags the need for further assessments, such as examining
different types of devices (such as ‘do smartphones differ from tablets in terms of the longer-term impact upon vision?’). It may be, based on what is known so far, that smartphones are more impactful as people hold them closer to their eyes and probably use them for longer period of time.
The Lancet study is titled “Association between digital smart device use and myopia: a systematic review and meta-analysis.”
