Night blindness

Night blindness is a symptom. It can be caused by many disease processes, both inherited and acquired, making accurate estimation of the epidemiology impossible. However, epidemiological data are available for retinitis pigmentosa and vitamin A (retinol) deficiency. WHO: global prevalence of vitamin A deficiency in populations at risk 1995-2005 Opens in new window Retinitis pigmentosa has a worldwide prevalence of 1 in 4000, affecting more than 1 million individuals. The disease has autosomal dominant (30% to 40%), autosomal recessive (50% to 60%), and X-linked (5% to 15%) inheritance.[3]Hartong DT, Berson EL, Dryja TP. Retinitis pigmentosa. Lancet. 2006 Nov 18;368(9549):1795-809. http://www.ncbi.nlm.nih.gov/pubmed/17113430?tool=bestpractice.com Vitamin A (retinol) deficiency varies worldwide and the epidemiological data have been collated by the United Nations Standing Committee on Nutrition. UN Standing Committee on Nutrition Opens in new window Reliable data are not available for rare genetic or acquired causes of night blindness.