Orthokeratatology are special contact lenses that a child wears overnight to correct blurry vision during the day. It is used to flatten or steepen the curvature while sleeping, reshaping the cornea to get clearer vision during the day. Ortho-K lenses only improves your vision for a short time. Once a child stops wearing the lenses, the cornea goes back to its normal shape and myopia recurs. However, it does provide reduction in myopia progression.