Biotechnology Blindness

How many people are blind worldwide?

In March 2021 I launched the Tej Kohli & Ruit Foundation to take low-cost cataract surgeries out into poor and remote communities in Nepal, Indonesia, Ethiopia, Tanzania, Myanmar, India and China. Working with my co-founder Dr Sanduk Ruit, I hope to cure 300,000 of cataract blindness by 2026.

In March 2021 I launched the Tej Kohli & Ruit Foundation to take low-cost cataract surgeries out into poor and remote communities in Nepal, Indonesia, Ethiopia, Tanzania, Myanmar, India, and China. Working with my co-founder Dr. Sanduk Ruit, I hope to cure 300,000 cataracts blindness by 2026.

The prevalence, causes, and impact of blindness are simultaneously well-documented whilst also being poorly understood by the general public. 90% of all blindness occurs in low-income countries, where those who suffer are quite literally ‘out of sight’ from the rest of the world.

In this #TejTalks blog post, I will curate the facts about blindness to aid better understanding. If you like this post please follow me on Twitter and Instagram.

Dr Sanduk Ruit operates on a patient of the Tej Kohli & Ruit Foundation to cure cataract blindness.

How Many People Are Blind?

  • In 2010 it was reported that the number of people of all ages who were visually impaired was 285 million (WHO visual impairment, 2010).
  • In 2020, 43 million people were believed to be blind (The Lancet Global Health Commission on Global Eye Health, 2021).
  • The number of blind people is expected to rise to 115 million worldwide by 2050 if the problem of unaddressed blindness is not dealt with.
  • In 2021 at least 2.2 billion people globally have a near or distance vision impairment. In at least 1 billion — almost half — of these cases, their vision impairment could have been prevented or has yet to be addressed (WHO, fact sheet, 2021).
  • 20 countries account for 77% of all visual impairment despite representing only 69% of worlds population.
  • China and India account for 45% of blindness and visual impairment (MSVI) despite representing only 36% of the world’s population.
  • Vision impairment poses an enormous global financial burden with the annual total global costs of productivity losses estimated to be US$ 269.4 billion (WHO, Fact sheet, 2021).
  • The leading causes of vision impairment and blindness are uncorrected refractive errors and cataracts (WHO, Fact sheet, 2021).
  • 94 million are affected by cataract worldwide with 65 million more having impaired vision due to cataracts (WHO, First world report on vision, 2019 & WHO, Fact sheet, 2021).
  • The major risk factors leading to an increase in the prevalence of vision impairment are population growth and ageing (WHO, Fact sheet, 2021).
Surgeons operate
Surgeons operate on a Tej Kohli & Ruit Foundation to cure cataracts.

Socio-Economic Factors Affecting Blindness

  • Blindness is significantly more prevalent in low income countries — 90% of the visually impaired are from low-income countries.
  • Malnutrition, inadequate health and education services, poor water quality and a lack of sanitation are all major risk factor for blindness.
  • In the low-income regions of eastern and western sub-Saharan Africa and South Asia, cataracts are responsible for half of the blind population (WHO, First world report on vision, 2019).
  • The Andra Pradesh Eye Disease Study from India reported that people from low and lower socio-economic strata had a five-to-ten-times increased risk of becoming blind.
  • Additional studies undertaken in India, Nepal and China have reported that those with no schooling have a three-times higher risk of blindness compared to those with some formal education.
patient waits for surgery
A patient waits for surgery to cure cataract blindness in Nepal.

How Does Gender Inequality Impact Blindness?

  • In most low and middle-income countries, women suffer socio-economic vulnerabilities and inequalities in their access to healthcare.
  • A global meta-analysis found that blindness in females is higher than men in all parts of the world. In Asia it is 39% higher and in Africa 41% higher.
  • Globally, women account for 64.5% of the blind population (Population-based prevalence survey, 2001).

Click the links below to explore #TejTalks blogs about gender inequality in healthcare and how blindness disproportionately impacts women:

How Many People Are Cataract Blind?

  • In 2020, cataract remained the first or second leading cause of blindness in all world regions (The Lancet Global Health 2021).
  • Cataract is responsible for nearly 20 million of the 43million people who are blind worldwide.
  • The number of people going blind from cataract is estimated to be 1 million per year.
  • In countries in South East Asia and India, in order to deal with cataracts in a sustainable way, it is necessary to perform 3000 surgeries per million of population each year (Vision 2020, the cataract challenge, 2000).
  • One study estimated that in India alone, around 3.8 million people turn blind from cataract every year (British Journal of ophthalmology, 1999).
  • The loss of productivity in countries like India due to blindness and severe visual impairment is estimated to be 0.4% of the GDP. It is predicted to increase to 0.8% by 2027. A 2009 study stated that a 0.25% of GDP was lost due to cataracts.
  • Blindness is therefore a significant drag on international development. The global productivity losses associated with the burden of all visual impairment is estimated to be $244 billion globally (WHO, fact sheet, 2021).

Is The Number Of Cataract Blind Increasing?

  • The rate of cataract surgery has increased over the past two decades globally, but cataracts still remain the leading cause of blindness in middle and low-income countries and accounts for 50% of all blindness (The lancet, Cataracts, 2017).
  • Industrialised ‘Western’ countries typically perform between 4000 and 6000 operations per million of population each year.
  • In middle-income countries, the rate of cataract surgery is between 500 and 2000 per million per year.
  • In countries like Africa and the poorer countries of Asia where cataract blindness is most prevalent, the rate of cataract surgery is less than 500 per million of population per year (Vision 2020, the cataract challenge, 2000).
  • This rate is sufficient to keep pace with the incidence of new cataracts.
  • Congenital cataract is also the most common worldwide cause of lifelong visual loss in children.
  • There are an estimated 200,000 children blind from cataract worldwide.
  • 20,000 to 40,000 children with bilateral cataract are born each year (Journal of Cataract and Refractive surgery, 1997).
  • In developing countries like India, 7.4–15.3% of childhood blindness is due to cataracts.
Patients await aftercare
Patients await aftercare after receiving treatment to cure cataract blindness at a microsurgical outreach camp of the Tej Kohli &Ruit Foundation.

How Many People Have Corneal Blindness?

  • According to the WHO, the fourth most common cause of blindness is corneal blindness, accounting for 12% of the 43 million global blind population (WHO, bulletin, 2001).
  • In developing countries, corneal blindness is the second most prevalent cause of blindness (Indian Journal of Ophthalmology, 2012).
  • India and Africa have a greater prevalence of corneal blindness , representing 15% and 30% of blindness in those countries.
  • 20% of childhood blindness is estimated to be due to corneal blindness (Nature, Eye, 2005).
  • A study in Nepal indicated that a unilateral corneal ulceration, which often leads to corneal blindness, typically occurs in 799 per 100,000 people (Bulletin of the WHO, 2001).
  • A south-India focused study in the early 2000s projected the prevalence of corneal blindness to grow from 0.6% in 2001to 0.84% in 2020 (British Journal of Ophthalmology, 2003).

Is Treating Corneal Blindness Difficult?

  • There are several major barriers faced by the medical community in developing countries which makes it extremely difficult to treat corneal blindness at scale.
  • Barriers include the limited availability of corneal tissues; low quality sutures, inadequate surgical instrumentation, the high cost of the tissue, poor institutional support, a lack of access to trephines and underdeveloped eye bank infrastructure.
  • Within the medical community, a lack of trained surgeons for keratoplasty also aggravates the growing backlog of untreated cases.
  • Economically disadvantaged patients with corneal blindness patients also cannot access hospitals for treatment due to the high cost.
  • Access to high quality steroid and antibiotic medications for many developing countries still poses a great challenge, due to cost and availability.

Can We Eliminate Needless Blindness By 2035?

  • In 2013, the World Health Assembly endorsed a GLOBAL ACTION PLAN (GAP) for Universal Eye Health (Universal Eye Health, 2013).
  • The target was to reduce prevalence of blindness and visual impairment by 25% in the10-year period between 2010 and 2019.
  • The WHO initiative ‘VISION 2020’ also had the aim to reduce the prevalence of visual impairments by 25% by 2019, but the target wasn’t achieved. A new target has since been set for 2030.
  • 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 to fund an additional 23 million health workers and to build more than 415,000 new healthcare facilities.
  • Unfortunately, so far there have been no reports of any meaningful progress in achieving the World Health Organization targets.
  • In fact due to ageing populations and population growth, the number of people who are needlessly blind is increasing worldwide.