Pärssinen O, et al. - Researchers investigated the influence of the definition of high myopia on its prevalence and factors conferring risk for high myopia in a randomized clinical trial including 240 myopic schoolchildren (119 boys and 121 girls, mean age =10.9 years) from 3rd- and 5th grades, who were referred for an eye examination because of poor distant vision and did not have previous spectacles. High myopia (spherical equivalent ≤ −6.00 D in either eye) in adulthood was found in approximately 32% of the children receiving first spectacles for myopia between the ages of 8.8–12.8 years. Large differences in prevalence were reported due to different definitions of high myopia ranging between −5 D and −6 D. Therefore, the requirement for a generally accepted definition of high myopia is highlighted. The factors that were found to be related to adulthood high myopia were: parental myopia, age at baseline, myopic progression during the first post onset year, and more time spent on reading and close work and less on outdoor activities in childhood.