Accelerated Ortho-K (AOK) contact lenses are able to reshape the corneas overnight, much like a retainer from your dentist helps correct the alignment of your teeth overnight.  This reshaping eliminates the need for visual correction during the day.  

Frequently Asked Questions:

How do ortho-k lenses work?

AOK shaping lenses are designed to progressively reshape the central surface of the cornea systematically to reduce nearsightedness.  The effect of AOK treatment is temporary and reversible.

Is AOK permanent?

After treatment, maximum results are achieved and retainer shaping lenses are worn to stabilize and maintain the corneal shape.  Failure to wear the retainer shaping lens on an ongoing basis will result in a return to the pre-existing prescription.  Retainer shaping will likely be prescribed for overnight wear.

How long does it take for the process to stabilize and provide functional vision for the whole day?

It generally requires four to seven consecutive nights of wearing the shaping lenses to achieve the desired result and up to 30 days to stabilize.  It may take somewhat longer for those with higher degrees of nearsightedness.

Are AOK lenses uncomfortable to wear?

Patients in clinical studies have said that overnight wearing of the shaping lenses is surprisingly comfortable.  Most patients are unaware of their presence within a very short time after insertion.  And because the AOK shapers are made in large diameters and worn during sleep, the normal adaption process is very short.

Will I still have to wear glasses or contacts?

Once the desired myopic reduction is obtained, the final shaping lenses act as retainers to maintain that level.  Regular contact lenses are not needed.  Glasses may be needed for reading or other part-time use.  During the initial treatment period, if unaided vision does not last a full day, the patient will be given soft disposable contact lenses to wear to maintain a normal distance vision.

Once the treatment phase is completed, how frequently will I need to wear the overnight retainer lenses?

Most people will need to wear the shaping lenses six to seven consecutive nights in order to enjoy good, unaided vision during the entire day.  Some patients with lesser degrees of myopia (nearsightedness) may find that wearing them every other night is satisfactory.  However, this will be determined on an individual basis by your optometrist.

How much myopia can a person realistically expect to be able to reduce using AOK?

Generally, 5.00 diopters of myopia is the upper limit for myopia reduction.

How about AOK for astigmatism?

The amount of astigmatism reduction achievable will depend on the amount and the type.  Generally, significant astigmatism cannot be corrected with AOK.  About 1.50 diopters of "with-the-rule" corneal astigmatism and 0.75 diopters of "against-the-rule" corneal astigmatism are considered the upper limits for astigmatism reduction.  AOK will not have an effect on residual (internal) astigmatism.

How long does it take to be able to see well without glasses?

Rapid visual improvement normally occurs in the first few days.  Stabilization then follows over the next several weeks.  Once the wearer's eyes are stabilized, improved eyesight is maintained by wearing shaping lenses as recommended by your optometrist to maintain vision at the desired level.

If I decide to return to wearing glasses, can vision be restored to its pre-treatment level?

The wearer's eyes will return to their pre-treatment nearsightedness after about two weeks.  Depending on how long AOK lenses have been worn, this process may be as long as 30-90 days.  In order to provide good vision during this transitional period, patients are refitted with gas permeable lenses or disposable soft lenses while the corneas return to their pre-treatment shape.

If I become less nearsighted or presbyopic in later years how will that be handled?

Corneal curvature can usually be remodeled to accommodate the change in prescription by changing the design of the maintenance lenses to correct for near vision.  This technique works in some patients and is called "monovision."

How safe is AOK?

AOK has been demonstrated to be safe when appropriately fitted and managed properly.  Many people have been able to eliminate their dependence upon their glasses and conventional contacts with no adverse effects.  As with all contact lenses, proper lens care and handling must be performed to maintain eye health.  The high-permeability GP materials now available provide adequate amounts of oxygen to the tissues of the eye.  There is a small risk involved when any contact lens is worn.

What are the risks of wearing lenses overnight?

The complications of wearing contact lenses whether you wear lenses on a daily basis or overnight for vision shaping may include temporary lens adhesion in the morning, corneal ingrowth of vessels, ulcers, and abrasions.  The risks associated with wearing contact lenses overnight are higher than wearing contact lenses only while awake.  Problems with contact lneses can result in serious injury to the eye.  Eye problems, including corneal ulcers, can develop rapidly and result in loss of vision.  You should carefully discuss the benefits and risks of overnight wear lenses with your optometrist.  It is important to adhere to the recommeded follow-up schedule to assure that continuing health of your eyes.  A good rule to follow for any contact lens wearer would be that if your eye is red or if there's any eye pain, remove the lenses immediately and consult your optometrist.  

What about the news reports that patients had parasites in their eyes from these lenses?

While unfortunate, the handful of unusual adverse effects cited by the media are isolated cases that are not representative of the thousands of patients in North America that achieve successful results from AOK and traditional contact lens wear.  However, such extreme outcomes reinforce the need to follow proper lens care regimen with eye care professional oversight.  Again, it is important to follow the rule that if your eye is red or if there is eye pain, remove the lenses immediately and consult your optometrist.  Tap water rinses are NOT recommended in caring for these AOK lenses. 

What about fitting children with AOK lenses whose corneas have not yet developed?

The human eye is 2/3 developed by 6 months of age and almost fully formed by the age 8.  The eye will grow approximately another 1 mm between the age of 8 and puberty, when it has reach full development.  Concerns for fitting children with AOK should be focused on the maturity of the child and on the willingness and participation of the parents in the fitting and care process and should be addressed by your optometrist.

I've heard that orthokeratology has been around for over 30 years.  Is this still the same process?

Modern orthokeratology uses sophisticated 4 and 5 zone designs that gently and gradually reshape the cornea to temporarily reduce myopia so no lens wear is required during the daytime.  These new designs are coupled with highly oxygen permeable GP contact lens materials that have only become available over the last several years.  Clinical studies over the last several years indicate that modern orthokeratology is a safe, effective, and reversible process with proper fitting, compliance and follow-up care with your optometrist.