A new report predicts that by 2050, half of the world's population (around 4.8 billion people) will be short-sighted. The medical name for this is myopia. It is also called near-sightedness. It is when things that are far away from us are difficult to see. There will be seven times more people with myopia in 2050 than there were in the year 2000. Today, almost 90 per cent of young Chinese people and up to 95 per cent of teenagers in South Korea are near-sighted.

The researchers said this increase was because of different things. Looking at computer screens and mobile phones could be a big reason. The rise may be linked to lifestyle changes resulting from spending less time outdoors. A science journalist said spending time outdoors in early childhood reduces the chances of getting myopia. A researcher of the report advised: "You could spend a long time [on] computers and screens, but also spend two hours outdoors."