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Visual Impairment & Blindness
Global Data & Statistics
Q4 2020 Update
Visual Impairment & Blindness
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.
Sections
Global Vision Impairment
Key Facts
0 Billion
people are estimated to live with a vision impairment of some description globally. Around 1 billion of these cases could have been prevented or have yet to be addressed.
0 Million
people are thought to have moderate or severe distance vision impairment in 2020. 55% are women and 89% live in low and middle-income countries.
0 Million
people are believed to be blind globally in 2020. This is set to increase to 115 million people in 2050
Main causes of vision impairment globally
| Million | Proportion | |
|---|---|---|
| Unaddressed Presbyopia | 826 | 80.12% |
| Unaddressed Refractive Error | 123.7 | 12.00% |
| Cataract | 65.2 | 6.32% |
| Glaucoma | 6.9 | 0.67% |
| Corneal Opacities | 4.2 | 0.41% |
| Diabetic Retinopathy (3 million) | 3 | 0.29% |
| Trachoma | 2 | 0.19% |
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)
MSVI
Blindness
Age-standardised and crude prevalence of moderate to severe visual impairment (MSVI) by country
Data Source: IAPB Vision Atlas
Global Trends
Whilst the number of people suffering from blindness and MSVI is increasing, the % of the population is decreasing
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:
- The increasing life expectancy and ageing population increased the numbers effected by 35%.
- The proportion of the population effected decreased by 37% over the 25 year period to 2015 due to a decline in poverty, a reduction of the incidence of certain conditions or later onset, better public health measures and improved eye health services.
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.
Population
Percentage
Chart by Merchant Savvy. Data by IAPD Vision Atlas.
Regional Differences
0 %
of visual impairment occurs in India & China
0 %
of all visual impairment occurs in just 20 countries
0 %
of visually impaired people live in low income countries.
Just 20 countries account for more than 3/4 of of visual impairments
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.
Top 20 countries with the highest number of people with blindness and moderate to to severe visual impairments
Data by IAPD Vision Atlas.
There is a clear relationship between average country income and visual impairment
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.
Top 20 countries by prevalence (age-standardised, all ages, both sexes)
Chart by Merchant Savvy. Data by IAPD Vision Atlas.
Visual Impairments are decreasing in every region
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.
Regional Prevalence of Visual Impairment
Chart by Merchant Savvy. Data by IAPD Vision Atlas.
Gender Differences
0 %
of those classed as moderate or severely vision impaired are women
0
is the ratio of women to men with blindness after controlling for age
0
is the ratio women to men with MSVI after controlling for age
Magnitude, temporal trends, and projections of the global prevalence of blindness and distance and near vision impairment: a systematic review and meta-analysis. Bourne et al, The Lancet (2017)
Prevalence of Blindness and Vision Impairment by Gender
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:
- Women were more likely to be blind or have vision impairment due to:
- Diabetic retinopathy (2.22)
- cataract (1.21)
- uncorrected refractive error (1.07)
- Men were more likely to be blind or have vision impairment due to:
- corneal opacity (0.54)
- glaucoma (0.71)
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.
Men
Women
Chart by Merchant Savvy. Data by The Lancet (2017)
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
WHO
The Impact of Age
0 %
of the global population aged over 50 (446 million) have near-vision impairment that could be corrected by glasses
The International Agency for the Prevention of Blindness (IAPB) Atlas
0 %
of the 253 million visually impaired people are aged 50 or older (203 million)
The International Agency for the Prevention of Blindness (IAPB) Atlas
0 %
decrease in number of blind children since 1990 largely due to a better control of measles and vitamin A deficiency
The epidemiology of blindness in children: changing priorities (Community Eye Health, 2017)
Everyone, if they live long enough, will experience at least one eye condition in their lifetime.
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 eye surgery.
MSVI
Blindness
Crude prevalence (%) of global population with moderate to severe vision impairments (MSVI) by age and gender
Chart by Merchant Savvy. Data by IAPD Vision Atlas.
Main Causes Of Sight Loss
0 Billion
people over the age of 35 have near-vision impairment (Presbyopia).
World blindness and visual impairment: despite many successes, the problem is growing. Community Eye Health (2017).
0 x
how many more people suffer from Presbyopia compared to other distance-vision impairments
The International Agency for the Prevention of Blindness (IAPB) Atlas
0 %
of all blindness and moderate or severe vision impairment (MSVI) is avoidable
The International Agency for the Prevention of Blindness (IAPB) Atlas
MSVI
Blindness
Contribution of each cause to moderate or severe vision impairment (MSVI)
among adults aged 50 years+ for the conditions below
Chart by Merchant Savvy. Data by The Lancet (2017)
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.
Number and percentages of those with preventable or treatable blindness (1990 to 2020)
Preventable or treatable is defined in this case as any vision loss due to cataract, uncorrected refractive error, trachoma, glaucoma, diabetic retinopathy, or corneal opacity
1990
158 million people
2010
190.6 million people
2020
222.6 million people
Global causes of blindness and distance vision impairment 1990–2020: a systematic review and meta-analysis, Flaxman et al. The Lancet (Oct, 2017)
Financial Implications
$ 0 Billion
productivity loss associated with the burden of visual impairment ($244B for myopia and $6B for myopic macular degeneration)
Potential Lost Productivity Resulting from the Global Burden of Myopia: Systematic Review, Meta-analysis, and Modelling. Naidoo et al. Journal of Ophthalmology (March 2019)
$ 0 Billion
The additional investment required to tackle vision impairment or blindness that could be prevented or has yet to be addressed
The World Report on Vision (Oct, 2019), The World Health Organisation
0 %
boost in productivity by providing affordable access to reading glasses
Cost of Poor Vision, World Economic Forum (2016)
More investment is needed to hit 2030 global health targets
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 $1.19 trillion each year.
The World Report on Vision (Oct, 2019), The World Health Organisation
In economic terms, there would be a huge productivity payoff by investing in eye health
The Investment required looks a no-brainer when you look at the estimated cost of lost productivity due to vision impairment globally. Even the cost of laser eye surgery looks relatively good value when put in this context.
| Age range | Cost in lost productivity due to Lack or Reading Glasses | % GDP |
|---|---|---|
| <50 Years | US$ 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 prevalence of avoidable vision impairment is not reducing fast enough to keep pace with this demographic change in the world’s population, so more attention to this problem is needed than has been given to it so far.”
The Lancet
Definitions
The International Classification of Diseases 11 (2018) classifies vision impairment into
- Distance vision impairment:
- Mild: presenting visual acuity worse than 6/12
- Moderate: presenting visual acuity worse than 6/18
- Severe: presenting visual acuity worse than 6/60
- Blindness: presenting visual acuity worse than 3/60
2. Near vision impairment:
- Presenting near visual acuity worse than N6 or M.08 with existing correction..
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