World health report

Conquering suffering, enriching humanity

Other issues

Blindness. An estimated 180 million people worldwide have visual impairments, of whom nearly 45 million are blind, four out of five of them living in developing countries. About 80% of blindness is avoidable (treatable or potentially preventable). However, a large proportion of those affected remain blind for want of access to affordable eye care. Blindness leads not only to reduced economic and social status but may also result in premature death. The major causes of blindness, and their estimated prevalence, are cataract (19 million), glaucoma (6.4 million), trachoma (5.6 million), onchocerciasis (0.29 million).

Some 121 million people are estimated to have a disabling hearing impairment. There is an urgent need for more, accurate population-based data on the prevalence and causes of hearing impairment, so that countries may set priorities and determine needs. As more countries conduct surveys, WHO collates the information so that an accurate global picture is progressively revealed.

Oral health. Dental diseases are chronic and adversely affect quality of life, especially in the elderly where they may have serious adverse effects on nutrition. Although great progress has been made over the last 20 years in combatting them, dental caries and periodontal disease remain the most prevalent. Caries, or tooth decay, is the more prevalent of the two.