Failure to address impaired eyesight is costing the world economy an estimated 121.4 billion dollars in productivity losses, according to research published by the World Health Organisation on Tuesday.
An estimated 158 million people suffer from uncorrected or undercorrected eyesight, including 8.7 million who were blind in 2007, according to an independent study by researchers in Australia, South Africa and the United States.
"If each affected person was provided with appropriate eyeglasses, we estimate that there may be a net economic gain, even if up to 1,000 dollars was spent per person to do this," said one of the authors, Tasanee Smith, of the John Hopkins Bloomberg School of Public Health in the United States.
The study estimated that the global loss in productivity due to impaired vision or blindness reached up to 427.7 billion dollars before being adjusted for employment rates and age.
However, the full cost of remedying eyesight deficiencies through provision of eyeglasses, surgery or other medical interventions was unknown.
The estimates were given in international dollars, a research tool used for historical comparison that has the same purchasing power as the US dollar at a given time.