CRT is a process which involves the wearing of custom-made hard (rigid) contact lenses when sleeping. The contact lens reshapes the cornea so that when the patient wakes in the morning and removes the contact lens their vision is improved. CRT provides freedom from spectacles and daytime freedom from contact lenses. CRT is non-invasive and completely reversible.


The original hard contact lenses were noted to reshape corneas even during day-to-day wear as early as the 1960s. This was seen as a design problem, so lenses were re-designed to eliminate this effect. The introduction of new lens materials and instrumentation in the early 1990s enabled this reshaping effect to be precisely and safely controlled by overnight hard contact lens wear.


CRT offers a lifestyle alternative for short-sighted people who play sports, work in dusty environments, or suffer from mild dry eye with soft lens wear in air-conditioned offices or for those that simply want the freedom of no spectacle wear. Its is suitable for those having a spectacle prescription of -0.75D up to -5.00D and astigmatism of up to -1.50D.

In addition, the latest research from Asia has shown that myopia can be slowed by up to 50% by CRT, so it may be suitable for teenagers or young adults who wish to decrease the rate of myopia progression.


The cornea can be divided into 3 broad layers. CRT affects the top layer only. During CRT a very thin layer of fluid is trapped between the back of the contact lens and the cornea, and this layer creates suction forces that encourage the top layer of corneal cells to move around.

For the treatment of short-sightedness, the corneal cells are moved away from the centre, effectively flattening the front corneal surface. As soon as the contact lens is removed, the corneal cells slowly start to return back to their original position with every blink, so vision returns to the original prescription. How quickly depends on the original prescription, but this usually takes longer than a day or so.


Initially, the contact lenses are worn ever night until an imprint is established. The wearing routine required to maintain the desired effect varies between individuals but can be as little as 2 nights per week. Many CRT patients wear their lenses 3 nights a week, whereas some must wear them every night to maintain adequate vision throughout the day. It is important to realise that CRT is not a part-time option, but a lifestyle commitment.


1)   The process of being fitted for CRT begins with a comprehensive eye examination, including scanning of eye curvatures using a topographer. This session takes around an hour.

2)   The optometrist then calculates the lens design required and selects the appropriate diagnostic lens.

3)   The optometrist delivers the diagnostic lenses, also teaching you about lens handling and care. You are then sent away to sleep in the lenses.

4)   You are later re-examined and your eyes are re-scanned the next morning to measure what imprint has been generated.

5)   This step is repeated if necessary with the same or different lenses.

6)   Following this measurement, your lenses are individually designed and ordered from the laboratory. Finally, you collect your lenses and attend for reviews as directed by the optometrist.

7)   Ongoing 6-monthly reviews are compulsory.


The lens trial is conducted so the optometrist can study the response of your corneas to the lenses, and for you to learn about comfort and handling issues before custom-made lenses are ordered. Often there is some degree of vision change during this fitting process.

Once the desired topography results are achieved the trial ends and the final lenses are ordered. This is the time to either commit or abort.


A bulk fee of $1680 is charged to cover all visits and lens costs involved in CRT. A 10% discount is provided If upfront payment is received. Alternatively, a payment plan is available which includes:

1)     A non-refundable fee of $345 for the initial trial

2)    An aftercare fee of $115 per visit for 5 visits = $575

3)    A contact lens fee of $760 or $500 (without warranty)

As a minimum, the consultation fees include:

Initial one-hour examination specifically for CRT
Diagnostic fitting visit
After-care examination after the first night's wear
Routine after-care visits at 1 week, 1 month, 3 months & 6 months
Other fitting visits as required

Replacements for lost or broken lenses are $249 per single lens.


A:   Yes, once the effect is complete you simply remove the lenses each morning and can see normally. You will also be able to see clearly with the lenses in when you wake up in the morning or the middle of the night.

A:   After the first night most of the necessary correction has been achieved. Normally within a week most of the effect has taken place and you will no longer be reliant on glasses or contact lenses.

A:  Yes. Research and experience show that the whole process is 100% reversible. So if you decide to stop wearing CRT for whatever reason, the eye will return to its original shape and you will see clearly with your glasses again. This makes CRT an excellent alternative to laser eye surgery.

A:  CRT lenses are made of the highest oxygen permeable materials for maximum comfort and safety during overnight wear.

A:  Yes, the procedure is reversible, simply stop wearing the lens and wear spectacles for several weeks.

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