Number of countries categorized by public health significance of night blindness 1995-2005a
The prevalence of night blindness is of moderate to severe public health significance in 45 countries for preschool-age children and 66 countries for pregnant women.
| Public health problemb | Preschool-age childrenc | Pregnant women |
| Number of countries | Number of countries | |
| None | 4 | 90 |
| Mild | 107 | 0 |
| Moderate | 42 | 66 |
| Severe | 3 | 0 |
a Excludes 37 countries with a 2005 GDP ≥US$ 15 000.
b The prevalence of night blindness as a public health problem in preschool-age children is categorized as follows: ≤0%, no public health problem; >0 - <1%, mild public health problem; ≥1 - <5%, moderate public health problem; ≥5%, severe public health problem. The prevalence of night blindness as a public health problem in pregnant women is categorized as ≥5%.
c Population groups: Preschool-age children (<5 years); Pregnant women (no age range defined).
Source
WHO. Global prevalence of vitamin A deficiency in populations at risk 1995–2005. WHO Global Database on Vitamin A Deficiency. Geneva, World Health Organization, 2009.