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What to expect

How do Ortho-K lenses work?

The cornea is a clear, dome-shaped window in the front of your eye that focuses light onto the retina and is responsible for most of the eye’s ability to focus. With Ortho-K vision technology, fully customized contact lenses are made to fit the exact shape of your eyes. As you sleep, your eyelid and the lens place gentle pressure on your cornea, it uses the forces of the tear fluid beneath the lens to reshape the cornea into a similar shape as the back of the lens design. For treatment of myopia, the lens produces a flatter central cornea and steepens the peripheral cornea, correcting short-sightedness by decreasing the power of the eye. The molding process is done by a precise, pre-determined treatment amount calculated using sophisticated 3D modelling of your eye shape.

Our corneal topographer precisely measures 102,000 individual points on your cornea, as unique as your fingerprint, to assist us in designing Ortho-K lenses that are uniquely yours. The machine doesn’t touch your eye, and there is no pain.

Immediate Improvement

Improvements in vision can usually be seen the next day, with the procedure stabilizing after generally one week. With high minus powers (myopia over -5.00D) the procedure takes two to four weeks to stabilize. Orthokeratology does not make any permanent changes to the eye surface. Your eyes will revert to their former state within one to four weeks if you stop using the lenses.

Who Can Benefit From Ortho-K?

They are the perfect solution for patients who:

  • Want a lens-free lifestyle during the day
  • Find soft contacts too irritating
  • Are too young for LASIK or are not a LASIK candidate

How can Ortho-K benefit my child with myopia?

  • Good vision all day. Perform better at school, playing sport and other activities.
  • Helps stabilize eyesight. Prevents significantly worsening vision year after year.
  • Healthier eyes for life. Reduce the risks of eye diseases and blindness.
  • Cost effective. Avoid thick and expensive high-index glasses over a lifetime.
  • No more worrying about breaking or losing glasses at school.
  • Easier to handle, insert & remove than regular soft contact lenses.
  • A happier child. Good vision can boost their confidence and self esteem.


There is no age limit for orthokeratology: children as young as six have been successfully and safely treated with these lenses by the optometrists. As orthokeratology has been shown to slow the progression of myopia (short-sightedness), it is one of the most common methods of vision correction in teenagers and pre-teens in our practice.

It certainly can. A large proportion of our patients are adults who use orthokeratology to decrease their dependence on using reading glasses. Orthokeratology lenses are a great option for adults as orthokeratology lenses do not dry out the eyes like soft contact lenses and can be designed to give both distance and near vision.

Infection is the main risk of all types of contact lenses, including Ortho-K. The risk of microbial keratitis in an Ortho-K wearer is extremely low (approximately 7 in 10,000 wearers, or just 0.07%), which is actually comparative far less than overnight extended-wear of soft lenses (0.52%). Even a daily-disposable soft lens wearer can be at risk if he or she doesn’t do the right thing. So the key to minimizing risk is to always follow the proper handling, hygiene and disinfection procedures for your lenses as recommended by your optometrist. There is no additional risk for a child wearing Ortho-K lenses compared to an adult. Can the orthokeratology contact lenses damage my eyes?

Dream lenses, sleep lenses, night lenses, Ortho-K, OK lenses, eye braces, Paragon CRT (corneal refractive therapy), VST (vision shaping treatment) — you may have come across different terms, marketing and brand names for orthokeratology lenses. While there are different orthokeratology lens fitting systems and designs, the main principles behind them are very similar.

We use the BE FREE orthokeratology fitting system. This uses sophisticated computer-aided modelling technology for the design of your lenses to your individual eye shape and parameters, as measured with our Medmont corneal topographer with a precision level measured in microns.

Unlike older Ortho-K fitting systems based on standardized fitting sets, such as Paragon CRT, our lenses are fully customizable to optimize myopia control effects for children, and to enhance vision clarity for adults. Our optometrist tailors each lens design to every individual’s own vision needs to ensure the best possible result can be achieved. A wider range of prescriptions, including high myopia (short-sightedness) and astigmatism can also be corrected with our advanced Ortho-K lens designs.

Dr. Vivian Zhang
B.S., OD.
Eyes that are open aren’t always seeing.
Book your eye exam today!