New research suggests that looking into the screens of our mobile gadgets for a long amount of time may cause short-sightedness.

Research published in the journal Opthalmology states that there is an influx of worsening eyesight in the world today with the coming of mobile gadgets. Half of the world may even have myopia by 2050 from looking at computer and smartphone screens for too long without spending enough time outdoors.

Myopia or nearsightedness is a condition where the eyes can see close objects but distant objects appear blurry. It is caused by refractive errors in the eye that disables the light from focusing on the retina caused by the length of one's eyeball or aging.

Researchers from Brien Holden Vision Institute, University of New South Wales Australia and Singapore Eye Research Institute predict that nearly half of the world's population or 4.8 billion people will need corrective glasses by 2050. In 2010, there are nearly 2 million or almost a third of world's population suffering from near-sightedness.

Up to 1 billion of those people will also have an increased risk of blindness by then. It suggests that technology by way of spending too much time looking at gadget screens contributes to the myopic population.

"Principally lifestyle changes resulting from a combination of decreased time outdoors and increased near-work activities," the researchers said. They added that high-income countries are at most risk as they spend most of their time with gadgets.

However, researchers at Ohio State University say that looking at computer screens does not cause myopia. Their two-decade study found that there is no association between eyesight and screentime among 4,500 children.

"Near work has been thought to be a cause of myopia, or at least a risk factor, for more than 100 years," lead author Karlda Zadnik, professor and dean of the College of Optometry at The Ohio State University said. "In this large dataset from an ethnically representative sample of children, we found no association."

In their research, they looked at 13 risk factors for myopia to create a prediction model for children who are at risk of being nearsighted.

They said that children with normal vision are slightly far-sighted and as they grow up, their eyeball becomes elongated. Therefore, children who are not far-sighted will tend to have myopia when they grow up.

"If you become near-sighted, it is because your eyeball has grown too long. This prediction model works," Professor Zadnik said.

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