What Is Ortho-K?
Ortho-K is vision correction that happens while you sleep. You wear a rigid, highly oxygen-permeable lens overnight. It gently and temporarily reshapes the front surface of your cornea. In the morning you take it out — and see clearly all day with no glasses and no contacts.
The effect is temporary and completely reversible. Nothing is cut, and no tissue is removed.
If you have arrived here searching for night lenses, sleeping contacts, overnight vision correction, corneal reshaping, corneal molding, dream lenses, or contacts you wear at night to correct vision — these are all names for the same treatment. The clinical term is orthokeratology, usually shortened to Ortho-K or ortho-k.
How Ortho-K actually works
The common assumption is that the lens presses the cornea flat overnight. It does not, and the real mechanism is more interesting.
An Ortho-K lens uses what is called a reverse-geometry design: flatter in the centre than the cornea beneath it, then steeper in a ring further out. Under a closed eyelid, that shape changes how the tear film sits between lens and eye. The tear layer redistributes the cornea’s outermost cells — thinning the epithelium slightly at the centre and thickening it in a ring around the edge.
That redistributed front surface has a flatter central curve, which brings light to focus correctly on the retina instead of in front of it. For a nearsighted eye, that is the whole problem solved.
Two things follow from this. First, only the outermost cell layer is involved — the epithelium, which naturally renews itself constantly. Nothing structural is touched. Second, because those cells keep renewing, the reshaping has to be renewed too. Stop wearing the lenses and the cornea drifts back to its original shape over days to weeks.
That reversibility is the point, not a limitation.
What the first two weeks are like
Most people see a large improvement after the first few nights. Vision then stabilises over one to two weeks as the cornea settles.
Higher prescriptions take longer, and some patients wear interim glasses for the first week while things settle. Vision that fluctuates early on — sharper in the morning, softening by evening, different from one day to the next — is expected, not a warning sign. It is the cornea finding its new shape.
Once settled, most wearers get a full day of stable vision from a night’s wear. A stable fit holds better than an unsettled one, which is one reason the follow-up schedule matters.
For the side effects worth knowing about in advance, and the symptoms that mean stop and call us, see are Ortho-K lenses safe?
Who Ortho-K suits
Children with progressing myopia
This is the best-known use, and the reason Ortho-K is fitted most often. When a child’s nearsightedness is increasing year on year, Ortho-K does two jobs at once: it corrects their vision during the day, and it is one of the established tools for slowing how fast the myopia progresses.
That second job is the one that matters long-term. Higher myopia carries higher lifetime risk of retinal problems, so slowing the progression is about more than avoiding thicker glasses. See myopia control in children and when to start myopia control.
The practical appeal for families is straightforward. A child who swims, wrestles, plays soccer or simply forgets where they put things does not have to manage glasses or daytime lenses at all. Correction happened overnight.
Adults who want their days lens-free
Ortho-K is not only for children, and this gets overlooked.
Adults choose it because they swim or do contact sports; because they work in dusty, dry or air-conditioned environments where daytime lenses become uncomfortable by mid-afternoon; because dry eye makes soft lenses a daily negotiation; or because they want to be free of glasses without surgery.
It is also worth considering if you are not a candidate for laser surgery — see Ortho-K vs LASIK — — because your cornea is too thin, your prescription is unstable, or you have dry eye that LASIK would worsen. Ortho-K asks nothing irreversible of your cornea, which is a materially different proposition.
Where Ortho-K is not the right tool
Being honest about this matters. Ortho-K works best for low to moderate nearsightedness, with or without a modest amount of astigmatism — see Ortho-K for astigmatism for where that limit sits. It is a poor fit if:
- Your prescription is outside what the lens design can reshape.
- You have significant dry eye or active ocular surface disease.
- You have had a corneal infection, or have certain corneal conditions.
- The nightly cleaning routine is not something you can commit to. That is a safety judgement, not a criticism — overnight lens wear is not something to do casually.
If Ortho-K is not right, it is not the only option. MiSight daily lenses, atropine and other approaches each suit different patients, and a fitting consultation is about working out which.
A note on irregular corneas: Ortho-K reshapes a cornea that is regular to begin with. If your cornea is already irregular — keratoconus, a corneal transplant, post-surgical ectasia — Ortho-K is not the answer, and scleral lenses are. Those vault over the cornea entirely rather than reshaping it.
Ortho-K, CRT and the brand names
You will run into several names, and they are less different than they sound.
Corneal refractive therapy (CRT) is the branded term for one of the two dominant Ortho-K lens designs in the United States, made by Paragon. Dream Lens and NightLens are other design names you may hear. All of them do the same job through the same mechanism; they differ in the geometry of the lens and the fitting software behind it.
Which design suits you is a clinical decision based on your corneal map, not a matter of preference. What matters far more than the brand on the box is whether the lens has been designed to your actual corneal shape and whether the fit is monitored properly.
How the fitting works
Corneal topography first. Before any lens is ordered we map the shape of your cornea in detail. Ortho-K lenses are designed to that map — this is not a matter of picking a stock lens off a shelf, and a lens fitted without a proper map is guesswork.
Design and order. The lens is designed to your measurements and manufactured for your eye. This takes a little time; it is not a same-day fitting.
Training before you take them home. Nobody leaves with lenses until insertion, removal, cleaning and storage have been demonstrated and practised in the office — with the parent included, for a child. Most of the problems seen with overnight lenses trace back to handling that was never properly taught.
Follow-up on a schedule. We check the corneal surface, the fit and the response over the settling period and then at regular intervals. Early changes are visible to us well before you would notice them, which is the entire reason the schedule exists.
What it costs
There is no single price, because an Ortho-K fitting is a process rather than a product: corneal mapping, custom lens design, the fitting itself, the training, and the follow-up visits over the settling period. We break down what drives the cost of Ortho-K in detail.
Michigan Contact Lens is out-of-network by choice, which means the clinical decision about your eyes is ours and yours rather than an insurance plan’s. We provide a detailed superbill you can submit for out-of-network reimbursement, and we accept HSA and FSA funds, CareCredit, and in-house payment plans. See Insurance & Payment Options.
Your initial consultation is complimentary, and you will leave knowing what your own fitting would involve before committing to anything.
Ortho-K in Southfield and Metro Detroit
Ortho-K is one of the specialty fittings this practice does most. Dr. Shira Kresch, OD, MS, FAAO fits Ortho-K and children’s myopia control at Michigan Contact Lens in Southfield, serving families and adults across Metro Detroit — Birmingham, Royal Oak, Troy, Farmington Hills, West Bloomfield, Novi, Oak Park, Huntington Woods, Rochester Hills and Detroit.
The equipment matters here. Corneal topography is what an Ortho-K lens is designed from, and we map every candidate before a lens is ordered. See our technology.
No referral is needed, and you can book directly.
Curious whether Ortho-K would work for you or your child?
Your initial consultation at Michigan Contact Lens is complimentary — corneal mapping, a clear assessment, and an honest answer about whether Ortho-K is the right tool.
Ortho-K Questions
- What is Ortho-K?
Ortho-K, short for orthokeratology, is a method of correcting vision using rigid, highly oxygen-permeable contact lenses worn while you sleep. The lens gently and temporarily flattens the centre of the cornea overnight. You remove it in the morning and see clearly through the day with no glasses and no daytime lenses. The effect is temporary and reverses completely if you stop wearing the lenses.
- How does Ortho-K work?
The lens does not press the cornea flat. It is designed with a reverse-geometry shape so that, under the closed eyelid, the tear film redistributes the cornea's surface cells — thinning the epithelium slightly at the centre and thickening it in a ring around that. That reshaped front surface focuses light correctly on the retina. Because only the outermost cell layer is involved, nothing is cut, removed or permanently altered.
- Are night lenses and Ortho-K the same thing?
Yes. Night lenses, nightlenses, sleep contacts, overnight vision correction, corneal reshaping, corneal molding and dream lenses all describe the same treatment. You may also see brand names such as Paragon CRT (corneal refractive therapy). They are different names and designs for one approach: reshape the cornea overnight, see clearly by day.
- How long does it take to work?
Most people notice a large improvement after the first few nights, and vision usually stabilises over one to two weeks as the cornea settles into its new shape. Higher prescriptions take longer and sometimes need interim glasses for the first week or so. Vision fluctuating early on is expected rather than a sign that it is not working.
- Can adults have Ortho-K, or is it only for children?
Adults can absolutely have it. Ortho-K is best known for slowing myopia in children, but plenty of adults choose it because they want clear vision without daytime lenses — for swimming, contact sports, dusty or air-conditioned workplaces, or because dry eye makes daytime lens wear uncomfortable. It is also an option for people who are not candidates for laser surgery.
- How long do Ortho-K lenses last?
The lenses themselves are durable and typically replaced on an annual basis, or sooner if your prescription changes or a lens becomes scratched or damaged. The corneal reshaping effect, by contrast, lasts only as long as you keep wearing them — it is maintained nightly, not banked.
- Is Ortho-K reversible?
Completely. Stop wearing the lenses and the cornea gradually returns to its original shape over days to weeks. No tissue is removed and nothing is permanently changed, which is a large part of why it is considered appropriate for children.
Ready to see clearly again?
Michigan Contact Lens fits scleral and specialty lenses for keratoconus, irregular corneas, corneal transplants, and severe dry eye.