estimated at 660 million (10 per 100 people) in 2013. Refractive Errors are the first common cause of Visual Impairment and second most common cause of visual loss . The assessment of Refractive Error is now done in DALY ( Disability Adjusted Life Years ) which showed an 8% increase from 1990 to 2019. The number of people globally with significant refractive errors has been estimated at one to two billion. Rates vary between regions of the world with about 25% of Europeans and 80% of Asians affected. Near-sightedness is one of the most prevalent disorders of the eye. Rates among adults are between 15-49% while rates among children are between 1.2-42%. Far-sightedness more commonly affects young children, whose eyes have yet to grow to their full length, and the elderly, who have lost the ability to compensate with their accommodation system. Presbyopia affects most people over the age of 35, and nearly 100% of people by the ages of 55-65. Uncorrected refractive error is responsible for visual impairment and disability for many people worldwide. It is one of the most common causes of vision loss along with cataracts, macular degeneration, and vitamin A deficiency. Cost The yearly cost of correcting refractive errors is estimated at 3.9 to 7.2 billion dollars in the United States. References External links Vision Disorders of ocular muscles, binocular movement, accommodation and refraction Refraction Wikipedia medicine articles ready to translate Wikipedia neurology articles ready to translate Corrective lenses