Orthokeratology existes for more than 50 years in its principles. However, we had to wait for the advent of high-precision lathes to really be able to offer, from the 90s onwards, multi-zone OrthoKs as we know them today. OrthoKs are now available in many countries and have even been very popular over the last 20 years for myopia correction in some regions (Asia, Russia, Eastern and Northern Europe, etc.).
On the other hand, OrthoKs for hyperopia are less widespread, although the first designs were available on the market in the early 2000s.
Indeed, they present a counter-intuitive aspect:
The central area must be tighter than the cornea in order to mold a lake of tears in the center of the cornea in the form of a small diameter protrusion.
The second zone forms a stabilizing band to keep the pressure stable for the central zone
After that comes a ring with a tear reservoir which supports the centring of the contact lens
Before the bevel is the alignment zone according to the given corneal radii and eccentricity.
This type of lens works well for hyperopia between +1.00 and +4.00.
How Orthokeratology for Myopia Works
How Orthokeratology for Hyperopia Works
The results are generally good. Positive optical corrections are rather low, so it is possible that the vision is already sufficient after the first night.