We now have two sets of global estimates on the magnitude, prevalence and causes of blindness – the Global Burden of Disease (GBD) Vision loss expert group and the World Health Organization’s Prevention of Blindness and Deafness Unit (WHO PBD) estimates.
The WHO PBD team released their estimates in 1995, 2002/4 and 2010. The GBD group has now created a ‘global vision database’, the largest systematic review of population-based published and unpublished data on vision impairment and blindness published between 1980 and 2012, and has brought out detailed estimates covering the period 1990 to 2010.
(A comparison of these datasets is available here: IAPB Briefing Paper on GBD data by Dr Kate Taylor)
A caution: Using estimates of the number of blind persons in the earlier PBD studies and comparing them with estimates for the number of blind persons from the 2010 GBD data set is not appropriate and can give rise to spurious claims.
The GBD data set presents a “good news” story:
- In 2010 there were nearly 100 million people fewer people who were blind or having severe or moderate visual impairment than would have been expected.
- Prevalence of blindness and visual impairment over the past twenty years – both globally and in every region – is declining. This is the most powerful evidence that the fight to eliminate avoidable blindness and vision impairment is being won
- The underlying rates of blindness in the low income countries is considerably greater than in high income countries
- The number of blind people in the world – 32 million. Those with moderate and severe visual impairment – 191 million. Total: 223.4 million
The GBD vision loss data can be used for the setting of priorities, advocacy, development of policies and planning.
IAPB now has a new Briefing Paper that builds a case for using the GBD data for these purposes. Do download the new IAPB Briefing Paper on GBD Numbers and Prevalence and use it in your work.