The use of concave lenses (lenses that depress inward) to correct nearsightedness is attributed to Nicholas of Cusa and the thought that specific lenses were required to ease various problems with vision prevailed for centuries.
Roughly 145 million of those people could have normal vision with the help of eyeglasses and are simply suffering from problems like nearsightedness, farsightedness, and astigmatism, and many are in low-income countries.
But if a child has become at least 0.25 diopters myopic at this age then there is a 60 percent chance that the child will require spectacle correction for nearsightedness by age 13.
The purpose of eyeglasses and contact lenses is to correct or improve the vision of people with nearsightedness (myopia), farsightedness (hyperopia), presbyopia, and astigmatism.
In addition, a child with undiagnosed nearsightedness related to Marfan may have difficulty seeing the blackboard or reading printed materials, and thus do poorly in school.