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Recent estimates suggest that nearly 45 million people worldwide fulfil the World Health Organization's criterion for blindness, defined as a best corrected vision of less than 3/60 in the better seeing eye.1 An additional 135 million people are visually disabled and in need of social, vocational, economic, or rehabilitative support services. To compound matters, more than 90% of all blind and visually disabled people live in the developing world, where common causes of bilateral vision loss include cataract, glaucoma, trachoma, vitamin A deficiency, and onchocerciasis. Additional causes of bilateral vision loss, which together comprise nearly one quarter of all blindness and which affect people in both developed and developing nations, include diabetic retinopathy and macular degeneration, among others (Fig 1). These numbers are projected to double within two to three decades unless innovative blindness prevention initiatives are undertaken in the near future.
It is against this backdrop that the editors of theBJO have elected to introduce a new column entitled “World view,” which will address issues pertaining to blindness prevention in the broadest sense. Hugh Taylor and Jill Keeffe provide the inaugural instalment for “World view” with their essay entitled “World blindness: a 21st century perspective” (p 261). Together, Taylor and Keeffe highlight some of the past successes in blindness prevention, including vaccination for smallpox and the introduction of Credé prophylaxis for the prevention of ophthalmia neonatorum in the 19th century, and the use of insulin to treat diabetes mellitus and the development of modern cataract surgery in the 20th century. Taylor and Keeffe caution, however, that the 21st century will present new, and possibly even greater, hurdles. Many people in developing nations still have no access to well established blindness prevention measures despite their long standing record of effectiveness in Europe and North America. In addition, the global population is both growing and ageing at a rapid pace. This means that both the prevalence of blindness and the absolute number of people with profound vision loss will increase dramatically, particularly vision loss due to cataract and other age related disorders, such as diabetic retinopathy and macular degeneration. Lastly, but most importantly, is the ever increasing realisation that functional blindness occurs long before vision drops to 3/60. In fact, Taylor and Keeffe suggest that “economic blindness” probably occurs once vision drops below 6/12, since vision below this level often affect a person's ability to drive and to function effectively in the workplace. Resetting this benchmark for functionally significant vision loss will, perhaps more than any other factor, magnify the global burden of blindness in years to come.
While world blindness may, at first glance, seem like an intractable problem, and to be sure many challenges lie ahead, a number of talented and dedicated vision researchers around the world are hard at work on blindness prevention. Many successes have already been realised, and the future, we believe, holds great promise. Yet, despite its undeniable importance, “World view” is the first column in an ophthalmology journal to be dedicated entirely to issues of world blindness. In some ways, “World view” is a work in progress. Feedback from our readers will be invaluable, therefore, to help shape this column as it evolves over the coming months. We look forward to your helpful comments and suggestions.
This work was supported in part by a career development award from Research to Prevent Blindness, Inc, New York, NY, USA.