General

• There are an estimated 45 million blind people and 135 million visually impaired people worldwide (World Health Organization. Global initiative for the prevention of avoidable blindness. WHO/PBL/97.61. Geneva: WHO, 1997)
• The global prevalence of childhood blindness is thought to be around 0.07%, or approximately one tenth of the prevalence of blindness in adults (Rahi et al. Measuring the burden of childhood blindness. Br J Ophthalmol. 1999 Apr;83(4):387-8)
• An estimated 1.4 million children are blind, 320,000 of whom live in sub-Saharan Africa (World Health Organization. Preventing blindness in children. Report of a WHO/IAPB scientific meeting. WHO/PBL/00.77. Geneva: WHO, 2000)
• The global financial cost of childhood blindness (based on the loss of future earning capacity) is thought to be between US$6 billion and $27 billion (Smith, AF and Smith, JG. The economic burden of global blindness: a price too high! Br J Ophthalmol 1996;80:276-7)
• Worldwide, up to 70% of childhood blindness may be preventable (Rahi et al. Measuring the burden of childhood blindness. Br J Ophthalmol. 1999 Apr;83(4):387-8)
• An estimated 3.1% of deaths worldwide are directly or indirectly due to cataract, glaucoma, trachoma and onchocerciasis (Murray, CJL and Lopez, AD. Global mortality, disability, and the contribution of risk factors: Global Burden of Disease Study. Lancet. 1997;349:1436-1442)
• Around 90% of people who are blind live in developing countries (World Health Organization. Global initiative for the prevention of avoidable blindness. WHO/PBL/97.61. Geneva: WHO, 1997)
• In developed countries, for each decade after the age of 40 there is a threefold increase in the prevalence of blindness and vision loss (Taylor, HR and Keeffe, JE. World blindness: a 21st century perspective. Br J Ophthalmol. 2001 Mar;85(3):261-6)
• In developing countries, it is believed that 60-80% of children who become blind die within 1-2 years (Lewallen, S and Courtright, P. Blindness in Africa: present situation and future needs. Br J Ophthalmol. 2001 Aug;85(8):897-903)

Regional

Diabetes

• around 5% of adults living in developed countries have been diagnosed with diabetes, and nearly all of these people will develop diabetic retinopathy if they live with the disease long enough (Shaw et al. Type 2 diabetes worldwide according to the new classification and criteria. Diabet Care. 2000;23:B5-10)

Cataract

• cataract is the leading cause of blindness in the world: in 1998, an estimated 20 million people were blind due to cataract (World Health Organization. The World Health report - life in the 21st century: a vision for all. Geneva: WHO, 1998;47).
• Globally, at least 100 million eyes have visual acuity <6/60 due to cataract (Foster A. Cataract--a global perspective: output, outcome and outlay. Eye. 1999;13:65-70)
• Annually, at least 25 million eyes develop visual acuity <6/60 due to cataract (Foster A. Cataract--a global perspective: output, outcome and outlay. Eye. 1999;13:65-70)
• Globally, the need for cataract operations is at least 30 million per year, but only around 10 million cataract operations are performed annually (Foster A. Cataract--a global perspective: output, outcome and outlay. Eye. 1999;13:65-70)

Glaucoma

• in the year 2000, an estimated 66.8 million people had glaucoma, due to which 6.7 million people suffered bilateral blindness (Quigley, HA. Number of people with glaucoma worldwide. Br J Ophthalmol. 1996 May;80(5):389-93)
• in developed countries, less than half of those who have glaucoma are aware that they have the disease, and in developing countries this figure is even lower. (Quigley, HA. Number of people with glaucoma worldwide. Br J Ophthalmol. 1996 May;80(5):389-93)

Trachoma

• 18%-24% of global blindness is due to trachoma, amounting to around 7 to 9 million people (Zhang et al. Risk factors for recurrence of postoperative trichiasis: implications for trachoma blindness prevention. Arch Ophthalmol. 2004 Apr;122(4):511-6)
• around 11 million people have trachomatous trichiasis, a complication of trachoma (Zhang et al. Risk factors for recurrence of postoperative trichiasis: implications for trachoma blindness prevention. Arch Ophthalmol. 2004 Apr;122(4):511-6)

Onchocerciasis

• An estimated 18 million people in the world have onchocerciasis (World Health Organization. Onchocerciasis and its control. Report of a WHO Expert Committee on Onchocerciasis Control 1995:1-104)
• At least 1 million people are blind or severely visually impaired due to onchocerciasis, making the disease the second leading infectious cause of blindness globally (Etya'alé, D. Eliminating onchocerciasis as a public health problem: the beginning of the end. Br J Ophthalmol. 2002 Aug;86(8):844-6)