With all that is positive about Ortho-K and their high percentage rates of slowing down the rate of increase Myopia (Nearsightedness), there are side effects that you have to look out for.
Ortho-keratology or Ortho-K is the usage of a specially designed gas permeable contact lens. It is a lens that gently reshapes the cornea or the front surface of the eyeball to reduce or control myopia. Myopia is referred as Shortsightedness or "Rabun jauh". Some people refer to it as Hard Lens or OK lenses. You wear these lens overnight and you can see clearly when you wake up. After you remove them of course.
Have you heard of the new technology known as Corneal Refractive Therapy (also known as Orthokeratology, Ortho-K ?