Successful treatment of blinding eye conditions has led to a lower prevalence of eye diseases than might be expected given the growth in population worldwide.
The finding is among the results of the largest review ever undertaken into global vision impairment and blindness, led by Professor Rupert Bourne of Anglia Ruskin University's Vision and Eye Research Unit in collaboration with 79 ophthalmologists and optometrists.
The review forms part of the Global Burden of Disease Study, funded by the Bill and Melinda Gates Foundation and published in a special issue of The Lancet (December 13). The study shows that, since 1970, men and women worldwide have gained more than 10 years of life expectancy but now spend more years living with injury and illness.
Visual impairment accounts for 21m years lived with disability (YLD) or 2.7 per cent of the overall global total. The largest cause of YLDs from visual impairment is 'other vision loss', primarily from trauma, occupational and idiopathic conditions. Uncorrected refractive error is second, while cataracts are the third largest contributor.
Professor Bourne said: 'The overall increase in the number of people suffering from blindness and vision loss is due to the huge population explosion that has occurred during the last couple of decades. However, the Global Burden of Disease findings actually show that this increase is not as large as one would expect given the increasing life expectancy in the world's population over this time.
'The age-standardised prevalence, which takes into account the changes in life expectancy, of blindness and visual impairment, decreased globally between 1990-2010. This points to the successful intervention in treating cataracts and other forms of blindness and infectious diseases such as trachoma.'
The work will be used to distribute resources and support VISION 2020: The Right to Sight, the global campaign to eliminate avoidable blindness.
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