- Over 285 million people in the world are visually impaired, of whom 39 million are blind and 246 million have moderate to severe visual impairment (WHO, 2011). It is predicted that without extra interventions, these numbers will rise to 75 million blind and 200 million visually impaired by the year 2020 (WHO, 2010).
Among persons who are blind worldwide:
- 58% are age 60+
- 32% are ages 45-59
- 7% are ages 15-44
- 4% are age 14 or under(Thylefors, et al., 1995)
- The number of people with partial sight today -- 135 million -- is expected to double by the year 2020 (Vision 2020, 2000).
- About 80% of blindness is avoidable (preventable or curable), and 90% of the world's blind live in a developing country (WHO, 2010).
- Globally, about 85% of all visual impairment and 75% of blindness could be prevented or cured worldwide (WHO, 2010).
- South East Asia and Western Pacific account for 73% of moderate to severe visual impairment and 58% of blindness (WHO, 2011).
Causes of Vision Impairment & Blindness
- The main causes of blindness are cataract (47.8%), glaucoma (12.3%) and age related macular degeneration (8.7%). Other causes include corneal opacity (5.1%), diabetic retinopathy (4.8%), childhood blindness (3.9%), trachoma (3.6%), and onchocerciasis (0.8%) (WHO, 2010).
- According to the World Health Organization (2010), Cataract is the leading cause of blindness in the world.
- 80% of global blindness is a result of five preventable or treatable conditions (cataract, refractive error, Trachoma, onchocerciasis and vitamin A deficiency) (Vision 2020, n.d.).
- Cataract results in blindness for 17.6 million people worldwide (Vision 2020, n.d.).
- Trachoma affects about 84 million people of whom 8 million are visually impaired (Vision 2020, n.d.)
- Nearly 67 million people worldwide have Glaucoma (Quigley, 1996).
- Glaucoma is the 2nd leading cause of blindness in the world (World Health Organization, 2006).
Other Causes of Blindness Worldwide
- Age-related Macular Degeneration affects 25-30 million people in some form (AMD Alliance International, 2002).
- Worldwide, 2.5 million people experience vision loss due to Diabetic Retinopathy (International Diabetes Federation, 2007).
- Every minute a child somewhere in the world goes blind (World Health Organization, 2009).
- Worldwide, approximately 1.4 million children ages 0-14 years are blind, defined as a corrected visual acuity in the better eye of less than 3/60 (Thylefors, Négrel, Pararajasegaram, & Dadzie, 1995; World Health Organization, 2009).
- More than 12 million children ages 5 to 15 are visually impaired due to uncorrected refractive errors as a result of near-sightedness, far-sightedness, or astigmatism (World Health Organization, 2009).
- Worldwide, vitamin A deficiency is the leading cause of childhood blindness, responsible for an estimated 70% of the 500,000 children who become blind each year (Thylefors, Négrel, Pararajasegaram, & Dadzie, 1995). According to the World Health Organization (Gilbert & Foster, 2001) there is a wide regional variation in the causes of blindness in children.
- The data indicate that the predominant causes of blindness among children in the poorest countries of the world include: corneal scarring due to vitamin A deficiency, measles infection, ophthalmia neonatorum, and the effects of harmful traditional eye remedies (Gilbert & Foster, 2001).
- In the United States, one out of 20 preschooler aged children will have a vision problem that affects their ability to learn (Prevent Blindness America, 2010).
National (US) Estimates
Self-Reported Visual Impairment & Low Vision
- Based on data from the 2004 National Health Interview Survey, approximately 19 million persons (8.8%) age 18 and over report having any trouble seeing, even when wearing glasses or contact lenses (Lethbridge-Cejku, Rose, & Vickerie, 2006).
- Based on data from the 1996 National Health Interview Survey, some degree of vision impairment, defined as blindness in one or both eyes or any other reported trouble seeing, affects 8.3 million (3.1%) Americans of all ages. (Adams, Hendershot, & Marano, 1999).
- Approximately 3% of individuals age 6 and older, representing 7.9 million people, have difficulty seeing words and letters in ordinary newspaper print even when wearing glasses or contact lenses. This number increases to 12% among persons age 65 and older (3.9 million) (McNeil, 2001).
- It is estimated that there are more than 14 million people in the United States with low vision (Peyman, 2001).
- Based on data from the 2004 National Health Interview Survey, , 61 million Americans are considered to be at high risk of serious vision loss if they have diabetes, or had a vision problem, or are over the age of 65 (Zhang et al., 2007).
- About 12 million people have some degree of visual impairment that cannot be corrected by glasses (National Advisory Eye Council, 1998).
Severe Vision Impairment
An estimated 1.8 million individuals age 15 and older (0.8%) are unable to see words and letters in ordinary print even when wearing glasses or contact lenses (Steinmetz, 2006).
Data collected from the National Health Interview Survey on Disability (1994-95) indicate that approximately 1.3 million persons reported legal blindness (0.5%) (cited in American Foundation for the Blind, 2007).
Light Perception or Less
An estimated 20% of legally blind individuals have light perception or less representing an estimated 260,000 individuals (American Foundation for the Blind, 2004).
Middle-Aged & Older Adults
The following estimates are based on findings from The Lighthouse National Survey on Vision Loss (The Lighthouse Inc., 1995). Vision impairment is defined as follows, based on self-reports:
- Inability to recognize a friend across the room, even when wearing glasses or contact lenses; or
- Inability to read regular newspaper print, even when wearing glasses or contact lenses; or
- Self-rated vision as poor or very poor even when wearing glasses or contact lenses; or
- Report of some other trouble seeing, even when wearing glasses or contact lenses; or
- Blindness in one or both eyes.
One in six Americans (17%) age 45 years of age or older, representing 16.5 million middle-aged and older adults, report some form of vision impairment even when wearing glasses or contact lenses.
The prevalence of vision impairment increases with age as indicated in the following estimates:
- 15% of Americans ages 45-64 years report some form of vision impairment, representing 9.3 million persons.
- 17% of Americans ages 65-74 years and older report some form of vision impairment, representing 3.1 million persons.
- 26% of Americans age 75 years and older report some form of vision impairment, representing 4.3 million persons.
- Among persons age 65 and older, an estimated 21% report some form of vision impairment, representing 7.3 million persons.
- According to studies using clinical measures to examine the prevalence of vision impairment among nursing home residents, estimates of vision impairment range from 21% to 52% (Morse, O'Connell, Joseph, & Finkelstein, 1988; Marx, Feldman, Werner, & Cohen-Mansfield, 1994; Horowitz, Balistreri, Stuen, & Fangmeier, 1995).
- Based on findings from the 1997 National Nursing Home Survey, 27% of nursing home residents age 65 and older (N=396,700) have a vision impairment (Gabrel, 2000).
- Nationally, 5.1% of persons age 18-44 (5.6 million) report trouble seeing even when wearing glasses or contact lenses. (Lethbridge-Cejku, Rose, and Vickerie, 2006).
- Among working age adults 21-64, an estimated 3.9 million report having difficulty seeing words and letters in ordinary newsprint even when wearing glasses or contact lenses. Of these 3.9 million working age adults, 800,000 are unable to see words and letters in ordinary newsprint even when wearing glasses or contact lenses (Steinmetz, 2006).
- An estimated 163,000 Americans ages 20-44, and 174,000 ages 45-64 are legally blind (Chiang, Bassi, & Javitt, 1992).
- According to the American Diabetes Association (n.d., a), diabetes is the leading cause of blindness in persons ages 20-74. An estimated 12,000 to 24,000 people lose their sight each year because of diabetes.
- Findings from the National Longitudinal Transition Study (NLTS) indicate that 57% of youth with visual impairments had attended postsecondary schools in comparison to 68% of the general population and only 27% of persons with disabilities overall (Blackorby & Wagner, 1996).
- Based on a 1998 survey of college freshman, 1.1% of all full-time freshmen report being "partially sighted" or "blind."
- Of college freshmen with any kind of disability, 13.3% report being "partially sighted" or "blind" - a decline from 31.7% reported a decade ago and 22.0% just two years earlier.
- Based on data from the 1996 National Health Interview Survey less than 1% (0.6%) of persons under the age of 18 are visually impaired, defined as blindness in one or both eyes, or have any other trouble seeing even when wearing glasses, representing 448,000 children and youths (Adams, Hendershot, & Marano, 1999).
- Based on data from the Survey of Income and Program Participation (Steinmetz, 2006), 189,000 children age 6-14 years of age (0.5%) have difficulty seeing words and letters in ordinary newsprint even when wearing glasses or contact lenses. Of those, 42,000 have a severe vision impairment (unable to see words and letters in ordinary newsprint), and 147,000 have a non-severe vision impairment (Steinmetz, 2006).
- In 1990, data on legal blindness indicated that approximately 2,600 children under 5 years of age and approximately 51,000 between the ages of 5-19 were legally blind (Chiang, Bassi, & Javitt, 1992).
- Among children under 5 years of age, prenatal Cataract is the leading cause of legal blindness, accounting for 16% of all cases. This is followed by optic nerve atrophy (12% of all cases) and Retinopathy of Prematurity (9% of all cases) (National Society to Prevent Blindness, 1980).
- Blindness occurs mainly among children with birth weights below 1,000 grams (2 lbs, 3 oz) at rates of 5% to 6% (Hack, Klein, & Taylor, 1995).
- A study of children in schools for the blind in the United States revealed that 19% of 2553 children were cortically blind, and 12% had visual loss from optic atrophy or optic nerve hypoplasia (Steinkuller, Du, Gilbert, Foster, Collins, & Coats, 1999; cited in Gilbert & Foster, 2001).
- According to state-reported data to the Office of Special Education Programs, 26,070 students ages 6-21 received vision services under Individuals with Disabilities Education Act (IDEA) during the 1997-1998 school year (U.S. Department of Education, 1999).
- Among students who have disabilities, students with sensory impairments are the most likely to graduate from secondary school with 73% of those with visual impairments doing so (based on data from the 1993-1994 school year (Kaye, 1997).
*Note: Percentages have been applied to Census 2000 population estimates to arrive at the number of persons reporting vision problems.
Nursing Home Residents
Young & Working Age Adults
Person Under Age 45:
Leading Cause of Vision Loss:
The following estimates are from the American Council on Education; HEATH Resource Center (Henderson, 1999).
Children & Adolescents
Severe Visual Impairment:
Causes of Blindness Among Children:
State estimates of vision impairment (based on visual acuity) among persons age 40 and older are available from Prevent Blindness America.