What is Ortho-k?

Ortho-k, also called orthokeratology, is a treatment using specially designed hard contact lenses, also called OK lenses, that corrects vision while you sleep. Ortho-k is sometimes called corneal reshaping therapy or Corneal Refractive Therapy(CRT). It uses specially designed rigid gas permeable(RGP) contact lenses to temporarily reshape the cornea (the clear layer on the front of the eye) while you sleep, allowing you to see clearly without the use of glasses or contact lenses during waking hours. During overnight wearing, the lenses gently reshape the front surface of the cornea. In the morning, you wake up to a world of clear, sharp, natural vision after removing the lens.

What is the treatment outcome?

(1) Correct myopia and achieve clear natural vision without wearing any glasses during the day.

(2) Effectively curb excessive myopia progression for children, to prevent children from developing high myopia or pathological myopia.

How does it work?

OK lens is designed with a flat centre and steep peripheral shape. It produces a mild pressure on the cornea and a hydrodynamic tear flow, which reshapes the cornea, thereby corrects the refractive error overnight.

Who are the candidates for Ortho-K?

A number of factors determine if a patient is suitable for Ortho-K. This includes health of the eyes, cornea shapes, degree of myopia and astigmatism. Individual assessment will be required to fully exam the condition of the eyes before the optometrist can decide if a patient is suitable and what the best treatment option might be. Currently, we are able to correct myopia up to -7.00D, astigmatism up to -3.00D depending on individual's suitability. As more advanced designs become available, it is possible that this range can be further extended.

Is Ortho-k safe?

Ortho-k has been used for vision correction for more than 50 years since it was first introduced in the 1960s. It is one of the most effective non-surgical treatments for myopia in the world to date. Its safety and efficacy have been validated by many clinical studies over the last 20 years. Under professional guidance, the risk of getting eye infection is very low.

How long does the clear vision last?

Patients can usually maintain clear vision throughout the waking hours. Some patients with low degree of myopia can even sustain a clear vision for 2 days. Talk to your optometrist if you feel you can see clearly throughout the day after skipping one night. Your optometrist will guide you on how regular you will need to wear the Ortho K lenses to effectively control myopia progression and maintain clear vision before bed.

Can adults have Ortho-k treatment?

Yes adults can have Ortho-K treatment and we offer Ortho-K to adults too. Ortho-K is an excellent option for adults who would rather not to wear glasses or contact lenses during the day for convenience; or for adults who need to participate in contact sports; or people working in a dusty environment that makes wearing contact lenses and glasses troublesome, or young adults who are waiting to have laser surgery but are not old enough to have stabilized vision. It is also a great alternative to laser surgery for those who are not ready for the permanent procedure.

More questions? You may find your answers on our frequently asked questions related to Ortho-K page.