Astigmatism is a very common optical condition of the eye that affects its ability to focus light on the retina. It affects around 20 to 30 percent of the population worldwide, with some estimates being as high as 50 percent. In the United States, the prevalence of astigmatism is estimated to be around 23 percent in those 18 years and older.
Astigmatism affects people of all ages but is much more common in children than in adults. It is estimated that up to 80 percent of children aged between 5 and 10 years old have some degree of astigmatism. In adults, the prevalence is estimated to be between 5 and 15 percent.
Astigmatism is also more common among certain ethnic groups. In the United States, it is estimated that nearly 50 percent of African Americans and 40 percent of Hispanics have astigmatism. In comparison, the prevalence among Caucasians is estimated to be around 20 percent.
Astigmatism can be caused by a number of factors, including genetics, the shape of the eye, and environmental factors. It is important that those with astigmatism have regular eye examinations so that they can be treated and monitored appropriately. Treatment for astigmatism typically involves corrective lenses, such as glasses or contacts, or, in more severe cases, surgery.