We’ve examined and compiled the most recent global data on visual impairment and blindness.
Whilst it is encouraging to see a continued decrease in the proportion of those suffering from visual impairment, there is still much work to be done to reduce the estimated 1 billion cases of visual impairment that could be prevented.
Increasing life expectancy and a continued rise in the global population, together with poor access to health care in some low income countries, means the overall numbers of blind and visually impaired people continues to increase.
We break down the statistics to look at trends across regions, causes, gender and age and also look at the financial implications of sight loss.
|Unaddressed Refractive Error||123.7||12.00%|
|Diabetic Retinopathy (3 million)||3||0.29%|
The 2.2bn figure was estimated by the WHO in 2019 based on epidemiological data reported by Fricke et al. (2018) in the American Academy of Ophthalmology and the report by Bourne et al published in the Lancet (2017).
The 2020 estimates for SSVI and Blindness come from the The International Agency for the Prevention of Blindness (IAPD Atlas)
Age-standardised and crude prevalence of moderate to severe visual impairment (MSVI) by country
The Vision Loss Expert Group (VLEG), who produced the data and estimates for the chart on the right, thought two main factors contributed to the increasing numbers suffering from blindness and vision impairment but a decreasing proportion of the population from 1990 to 2015:
Their estimate for the prevalence of vision loss in 2050 assumed the global population would to increase from 7.8 billion in 2020 to 9.7 billion in 2050.
As would be expected, the 20 countries with the highest number of people with blindness and moderate to to severe visual impairments closely resemble those with the largest populations. However, what is more surprising is that these 20 counties account for 77% of all visual impairment but 69% of the total world population.
With a relatively large number of people over 50, the highest incidence of visual impairment in these areas is predominantly related to a high population of elderly people.
China and India account for 45% of all cases of blindness and MSVI but only 36% of the world’s population.
What is more revealing is the proportion of those with visual impairments in each country which can be see in the chart below. These reveals the close correlation between the prevalence of visual impairments and country income.
The 20 countries estimated to have the highest prevalence visual impairment are dominated by low income countries.
Over 70% of Sub-Saharan Africa suffer from near-vision impairment due to uncorrected Presbyopia. A simple pair of spectacles could fix each case.
Progress is being made though. Over the 25 years from 1990 to 2015, 90 million people were treated or prevented from becoming blind or moderate or severely vision impaired.
Whilst the visual impairments are still most prevalent in lower income countries the proportion of those experiencing sight loss is dropping in all areas.
The biggest decreases in the prevalence of visual impairments have been seen in South Asia, North Africa and the Middle East.
The advancements of modern medicine hasplayed a significant role in the improvement of visual impairment rates worldwide. More affordable eye surgeries, new technologies and new treatments are all reducing the prevalence.
It is also that improvements in hygiene, better management of medication and increased access to nutrition has lead to a significant reduction in visual impairments caused by a lack of vitamin A, parasites, or unhygienic habits.
Women suffer the most from vision impairment and blindness in all regions of the world.
The relative odds ratio of women versus men of the main causes can be seen in brackets below:
There was no significant difference between the genders for age-related macular degeneration.
The major difference between the genders starts from 50 years old and difference increases with age which is largely due to women outliving men by 6 to 8 years on average.
The gender disparity is not the same for all countries, although it doesn’t seem to be directly connected with high or low-income countries.
The world faces considerable challenges in terms of eye care, including inequalities in the coverage and quality of prevention, treatment and rehabilitation services; a shortage of trained eye care service providers; and poor integration of eye care services into health systems, among others
As you can see from the chart visual impairments are thankfully quote rare in those under the age of 40. However a global systematic review and a meta-analysis reported that the number of children and adolescents with myopia is expected to increase by 200 million between the years 2000 and 2050.
Amongst those aged over 40, presbyopia is the most condition as the condition is naturally caused by the ageing of the eye, compromising its ability to focus and it usually start to develop and worsen after 35 to 40 years Indeed, presbyopia is responsible for around 80% of the cases of vision impairment globally.
But if you lived long enough without any eye condition, chances are you’ll get at least presbyopia. It can be treated with eyeglasses, contact lenses, and in some cases laser surgery.
Contribution of each cause to moderate or severe vision impairment (MSVI)
among adults aged 50 years+ for the conditions below
Data are mean (80% uncertainty interval)
Note: The The main types of refractive errors are myopia (nearsightedness), hyperopia (farsightedness), presbyopia (loss of near vision with age), and astigmatism.
The World Health Organisation has estimated that in order to achieve the global eye health targets set for 2030, low- and middle-income countries will need to invest $14.3 billion in order fund an additional 23 million health workers and build more than 415,000 new health facilities.
The global burden of uncorrected Presbyopia alone is estimated to be just over $11 billion annually in terms of lost productivity.
Given that 74% of illiterate adults failed one or more parts of a vision screening it is also thought that providing affordable access to reading glasses would also help bring down levels of illiteracy which costs the global economy $1.19 trillion each year.
Investment required looks a non-brainer when you look at the estimated cost of lost productivity due to vision impairment globally.
|Age range||Cost in lost productivity||% GDP|
|<50 Years||US$ 11.02 Billion||0.016|
|<65 Years||US$ 25.37 Billion||0.037|
The WHO initiative VISION 2020 had the aim to reduce the prevalence of visual impairments by 25% until 2019.
Unfortunately so far there has been no reports of the VISION 2020 goal of being met worldwide or in targeted countries and regions, causing WHO to change their plans for 2030.
The World Report on Vision (Oct, 2019), The World Health Organisation
Global Prevalence of Presbyopia and Vision Impairment from Uncorrected Presbyopia (Fricke et al, 2018), American Academy of Ophthalmology
Cost of Poor Vision, World Economic Forum (2016)
The epidemiology of blindness in children: changing priorities (Community Eye Health, 2017)
The International Classification of Diseases 11 (2018) classifies vision impairment into
2. Near vision impairment:
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