Paraguay and Uganda, at about 1%, had some of the lowest levels of myopia, with the UK, Ireland and the US all about 15%.

The study, published in the British Journal of Ophthalmology, external, looked at research involving more than five million children and teenagers from 50 countries across all six continents.

Their number-crunching revealed that short-sightedness tripled between 1990 and 2023 – rising to 36%.

And the increase was “particularly notable” after the Covid pandemic, the researchers say.

Myopia usually starts during primary school years and tends to worsen until the eye has stopped growing, at about 20 years of age.

There are factors that make it much more likely – living in East Asia is one of those.

It is also down to genetics – the traits children inherit from their parents – but there are other factors too, such as the particularly young age (two years old) that children start their education in places like Singapore and Hong Kong.

This means they are spending more time focusing on books and screens with their eyes during their early years, which strains the eye muscles and can lead to myopia, research suggests.

In Africa, where schooling starts at the age of six to eight years old, myopia is seven times less common than in Asia.