长时间看屏幕会影响孩子的视力？

在多屏幕的现代社会中，孩子们的日常生活被各种电子屏幕所包围。他们每天要做的很多事情都涉及长时间盯着一种电子设备屏幕，而有越来越多的证据表明长时间看屏幕会使孩子的视力下降，造成近视。

These days there is so much tempting technology to look at: smartphones, tablets, computer games and TV screens. Much of our entertainment and education comes from using them, so it's no wonder we spend so much time staring at them. But even if the saying that looking at a screen for too long gives you square eyes isn't true, there is still some concern that it can affect your eyesight. So, should we be worried?

Certainly for children who spend hours glued to a screen there is a concern that their health might be at risk. The lack of physical activity can lead to an increase in their weight. But there is a fear that their eyesight is deteriorating too. Although there's not much evidence to prove this yet, recent findings have opened our eyes to the issue.

Katherine Sellgren from BBC News spoke to Chris Hammond, professor of ophthalmology at King's College London and consultant ophthalmic surgeon at St Thomas' Hospital. He said "We know that myopia, or short-sightedness, is becoming more common… It has reached epidemic levels in East Asia, Singapore, Taiwan, South Korea, where approaching 90% of 18-year-olds are now short-sighted."

But can this be linked to children's obsession with using electronic gadgets? Annegret Dahlmann-Noor, consultant ophthalmologist at Moorfields Eye Hospital in London says lack of natural light seems to be the key issue. She's suggested that children in East Asia study a lot, using computers, smartphones or tablets, and they are go outside less, which could be a cause of short-sightedness. Wearing glasses is one solution, but it's not ideal.

This leads to a dilemma: achieving short-term academic success or protecting your long-term eyesight. It's always going to be a challenge to drag children away from their screens and it's likely that more and more studying will be done online, through a screen. But despite that, Professor Hammond says, "in countries like urban China, where 10% of children in each class per year are becoming short-sighted from about the age of six, there's an argument for saying we should be trying to prevent it." It's evidence we can't turn a blind eye to. So, maybe it's time to hit the 'off' button and get our children outside?