If you don't already wear eyeglasses, there's a good chance you will by the middle of this century.

A new study predicts that by 2050, 4.8 billion people -- about half the global population -- will be afflicted with nearsightedness, or myopia, a common eye malady that causes distant objects to appear blurred while close objects can be seen clearly.

That would be a threefold increase from 2000. Additionally, one out of 10 people are predicted to be at risk of blindness.

A likely culprit in the surge in myopia, called shortsightedness in some parts of the world, is the amount of time people are spending inside, staring at computer and cellphone screens , according to the study, published online Feb. 11 in the journal Opthalmology.