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Night Lenses

(nighttime MCT contact lens)
slow down myopia + daytime spectacle free
monitor eyeball length and myopia progression

Orthok / nighttime contact lens


Nature + Nuture

Night Lenses (Orthokeratology)

(OrthoK, OK-lens, MCT, Corneal Refractive Management, Corneal moulding)

The information below is a general review of the concept of orthokeratology lens. You may  call us (Tel: 21530008) for detail information.


What’s Night Lenses / OK-lenses?

Night Lenses / OK-lenses (Orthok) are a safe and effective way to correct your vision without the need for surgery. They work by reshaping your cornea with the use of special contact lenses that are worn at night while you sleep, providing clear vision during the day without the need for glasses or daytime contacts. Orthok is also a type of myopia control technology and can help manage dry eye. The treatment is carried out under the supervision of an optometrist and has been shown to reduce moderate myopia and astigmatism. Research has also demonstrated that Orthok may help stop or slow down the progression of myopia in children [1].

Aim of Night Lenses / Orthokeratology:

1. *daytime spectacle free

2. myopia control

3. contact lens option for dry eye cases

Axial length 眼軸長度

Long eyeball axial length will increase chance of eye diseases!

damage caused by high myopia


Night Lenses

*daytime spectacle free

Orthokeratology mechanism

With modern MCT orthokeratology, the specially designed contact lenses can reshape the cornea while ensuring high oxygen flow for the eyes. The process requires a precise assessment of the corneal profile to achieve the best results. This is done using a state-of-the-art corneal topographer, which is a shape and profile scanner that ensures high accuracy during the entire process. With this advanced technology, optometrists can monitor the corneal shape modification and make adjustments as needed, providing peace of mind for wearers and parents who want the best for their children's vision.

sMap3D orthok.jpg

Precision Optics Corneal Topographer

•  32 Rings 
•  102,000 Analysed Points
•  9600 Measurement Points 
•  Composite Mapping Coverage 0.25mm to 14mm
•  Extrapolated Data Out to 17mm
•  Power Range 10 - 100 Diopters

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sMap3D orthok 3.jpg
8D orthok.jpg
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Candidate for Orthok

Help children enjoy fun of reading

Who are suitable for night lenses (orthokeratology)?

- at least 7 years old
- Less than -6.00D of myopia and with less than -2.00D of astigmatism. (For those with myopia stronger than -6.00D or corneal astigmatism higher than -1.50D, full bespoke specialty orthokeratology lens may be needed.)
- Myopia are progressing rapidly.
- Sports and water sports enthusiastic, e.g. swimming, diving, skiing.
- For those not suitable for LASIK refractive surgery

- For those with dry eye problem associated with soft contact lens

Myopia Damages Eyes

orthok induced defocus control myopia

1. *Good vision can usually be maintained throughout the day after lens removal.
2. Recent research has shown the usage of Ortho-K to be effective in slowing myopic progression in children [1] .
3. Ortho-k can reduce myopia of 5.00D within two weeks. However, individual variation does exist.
5. Complications associated with conventional contact lens wear, such as dryness and irritation from dust can be avoided.
6. Safe alternative to LASIK laser refractive surgery with no wounds and no dry eyes.
7. The Orthok-K effect is reversible and can be stopped anytime. The eyes will soon resume their normal condition thereafter.

1. Ortho-k is NOT a CURE for myopia. The Ortho-K effect will wear off gradually after cease of lens wear.
2. Aftercare consultations are necessary to ensure effectiveness and safety.
3. Some contact lens-related problems, such as solution sensitivity, infection, corneal epithelial trauma or ulceration may occur, though the risk of complication is very dependent on compliance.

orthokeratology schedule

Attention! *To ensure the best vision for your child, it's important to understand that there are various factors that can affect their daytime vision. Sometimes, they may still need low power glasses for certain visual purposes even with Ortho-k treatment. While complications can happen, you can minimize the risk by maintaining good communication with your optometrist, strictly following their instructions, and attending regular checkups. If your child is unable to handle their contact lenses hygienically, it's important for parents to be prepared to assist them or consider alternative treatments. We are committed to ensuring the safety and success of your child's Ortho-k treatment.

1. Cho P, Cheung SW. Protective Role of Orthokeratology in Reducing Risk of Rapid Axial Elongation: A Reanalysis of Data From the ROMIO and TO-SEE Studies. Invest Ophthalmol Vis Sci 2017;58(3):1411-1416.

orthok orthok

**Case Examples:

**Case Example 1.:

- Calvin had myopia -2.50 binocularly. Since 1o years old, he put on night lenses (orthokeratology lenses) every night. At daytime, after removal of lenses, his residual prescription was around farsighted +0.75 to +1.00. He achieved functional vision without spectacles at daytime.

- Eight years later, he went to USA for university education. The nighttime contact lens wearing frequency was reduced to four times per week.
- At 18 years old, Calvin's myopia was right eye -2.50, left eye -2.75.

Portrait of a young Asian boy wearing tr
Case examples

**Case Example 2.:

- Joan had myopia -3.50 binocularly. Since 13 years old, she put on night lenses (orthokeratology lenses) every night. At daytime, after removal of lenses, his residual prescription was around farsighted +0.50 to +0.75. She achieved functional vision without spectacles at daytime. 

- Five years later, she went to Australia for medical school training. The wearing frequency of nighttime contact lenses was reduced to five times per week.
- At 22 years old, Joan's myopia was maintained -3.50.

Doctor and Asian young woman looking at
Active woman in her 50s running and jogg

**Case Example 3.:

- June had myopia -5.00 and presbyopia (reading problem) +2.00. since 50 years old, she cannot tolerate soft contact lenses because of severe dryness.

-  By use of night lenses (orthokeratology lenses), she can manage her driving and reading tasks without spectacles. Her residual prescription was usually +0.25 to +0.50 for right eye and -0.75 for left eye.

-   She was very happy without need of reading glasses.

**To comply with privacy regulation, the aforementioned case information was modified.

Our optometrists


More services

Eye Exam

Our Centre provides eye test for Adults and children from two and half years old. The eye test covers refractive errors, visual functions and eye health assessment.

​Progressive spectacle lenses + Multifocal contact lenses

We are well experienced  in progressive spectacle lenses and multifocal contact lenses fitting for management of presbyopia.

Myopia control & Orthokeratology


our centre also provide myopic control and orthokeratology service to kids and teenagers on indication.

Specialty contact lens services

In our center, we fit specialty contact lenses, such as rigid gas permeable (RGP) lenses, hybrid lenses and scleral lenses.

​Health Care Voucher

Our optometrists are appointed Health Care Service Providers of Health Care Voucher Scheme. Eligible Elderly may use Health Care Voucher for payment of eye examination and eyeglasses fee. For more information, you may contact us by telephone number 21530008 for eye examination booking.

Contact us
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