What Ortho-K Is
What is Ortho-K?
Ortho-K is the use of custom rigid gas-permeable lenses, worn during sleep, to gently and temporarily flatten the central cornea. Removing the lenses in the morning leaves the cornea in its treated shape for the rest of the day, which corrects nearsightedness without glasses, daytime contacts, or surgery. The change is temporary and maintained by nightly wear.
The cornea is the clear dome at the front of the eye, and it performs roughly two thirds of the eye's focusing. In a nearsighted eye that dome is slightly too steep relative to the length of the eyeball, so incoming light comes to a focus in front of the retina and distance objects blur. An Ortho-K lens redistributes a microscopic amount of tissue in the outermost corneal layer overnight, flattening the center by a few microns. That is a fraction of the thickness of a human hair, and it is enough to land the focal point back on the retina.
Two things follow from that mechanism and they shape everything else on this site. First, because no tissue is cut or removed, the treatment is reversible and appropriate for eyes that are still developing. Second, because the effect is maintained rather than fixed, results depend on wearing the lenses consistently and on the lenses being designed accurately for your specific corneal shape.
Start with What Is Ortho-K for the full explainer, or go straight to How Ortho-K Works if you want the optics in detail.
How the Overnight Effect Happens
An Ortho-K lens is not a stronger contact lens. It is a mold with a deliberately unusual shape. The center is flatter than your cornea, a ring just outside the center is steeper, and the outer zones align with the corneal periphery to keep the lens centered and to let tears circulate underneath. That geometry creates a controlled pressure differential across the corneal surface during the hours you sleep.
Under that lens, cells in the corneal epithelium redistribute. The central epithelium thins slightly and the mid-peripheral epithelium thickens slightly. Nothing is destroyed and no deeper layer of the cornea is altered. The stroma, the thick structural layer that refractive surgery reshapes with a laser, is essentially untouched.
Most patients notice a large improvement after the first night. Vision generally keeps sharpening for one to two weeks as the corneal surface settles into a stable treated shape, and higher prescriptions usually take longer to get there. The full mechanism, including why the same optics appear to slow eye growth in children, is covered in How Ortho-K Works.
The Invisalens Overnight System
Invisalens is the name of the overnight Ortho-K system used at Better Sight Overnight. It is not a different physical principle from Ortho-K generally. It is a defined way of delivering it, and the difference between a good Ortho-K result and a mediocre one is almost always delivery rather than principle.
- Designed from your topography, per eye. Lens parameters are calculated from a three-dimensional map of your own cornea. Your two eyes are almost never identical, so they are designed separately rather than as a matched pair.
- High Dk gas-permeable material. Overnight wear puts oxygen transmission at the center of safety. Invisalens lenses are made in high-oxygen materials chosen specifically for closed-eye wear.
- Training you have to pass. Lenses do not leave the office until the patient or parent can insert, remove, and clean them independently in front of us.
- A follow-up schedule that is part of the program. Next morning, one week, one month, then three and six months, with topography compared against baseline at each checkpoint.
Read the full description of the system, including what we do differently at the design stage, on the Invisalens Overnight System page.
Explore Ortho-K in Depth
These eight pages cover Ortho-K from first principles through candidacy. Read them in any order.
- What Is Ortho-K. The definitive explainer: the definition, the anatomy, what a night of wear actually involves, and who is and is not a candidate.
- How Ortho-K Works. The optics in depth: reverse-geometry lens zones, epithelial redistribution, tear film forces, and peripheral myopic defocus.
- The Invisalens Overnight System. Our branded system: topography-guided design per eye, high-oxygen material, and structured follow-up.
- Clear Vision Without Surgery. How overnight correction compares with LASIK and PRK on permanence, risk, age limits, and recovery.
- Benefits of Overnight Vision Correction. What Ortho-K delivers for children, teens, athletes, and adults, plus the tradeoffs worth weighing.
- Ortho-K for Myopia. Which nearsighted prescriptions respond predictably, what partial correction means, and how candidacy is decided.
- Ortho-K for Astigmatism. Toric overnight designs, which astigmatic eyes respond, and where the honest limits are.
- Reversible and Non-Surgical. What reversibility actually means and exactly what happens if you stop wearing the lenses.
Who Ortho-K Suits
Ortho-K tends to fit two groups particularly well: people whose daily life is genuinely harder with glasses or daytime contacts, and children whose prescription climbs at every annual exam.
- Children with progressive myopia. The strongest clinical case, because Ortho-K corrects vision and creates the optical conditions associated with slower axial elongation at the same time.
- Teens. Old enough to own the routine, motivated by sports, driving, and not wanting to wear glasses.
- Adults. Daytime freedom without a permanent procedure, including adults whose corneas are too thin for surgery.
- Athletes. Swimming, contact sports, dust, sweat, and helmets all stop being eyewear problems.
- People who cannot tolerate soft contacts. Dryness and end-of-day discomfort mostly disappear when lens wear happens while you sleep.
- People weighing LASIK. The same daytime outcome without permanence, and available years before surgery would be appropriate.
For children, the reason to act is not convenience. Myopia progression reflects the eyeball physically lengthening, and that lengthening is permanent. See Myopia Control and Slowing Progression for what the evidence supports and what it does not.
Safety and Honest Limits
Ortho-K has been in clinical use for decades and modern designs in high-oxygen materials have a well-documented safety record. The main risk is the one shared by any overnight contact lens wear: microbial keratitis, a corneal infection. Reported rates in Ortho-K are broadly comparable to overnight soft lens wear, and hygiene compliance is by far the largest factor a patient controls.
Read Is Ortho-K Safe, Risks and How We Minimize Them, and Realistic Expectations before you decide. The clinical evidence page collects the research behind these claims.
What Ortho-K Costs
A complete custom Ortho-K program at Better Sight Overnight starts at $1,800. A standalone candidacy consultation starts at $250 and is credited toward your program if you go ahead. For children and teens, the ongoing myopia control program starts at $1,200 per year after the initial fitting. You receive your exact figure in writing before you commit.
The program price is a system rather than a deposit. It covers the consultation, corneal topography, custom design for each eye, the lenses themselves, handling training, a starter care kit, and the first month of follow-up visits. Your specific number depends on prescription and corneal complexity.
See Cost and Investment for the full picture, including what is included, financing, insurance, and long-term value compared with years of glasses and soft lenses.
Getting Started in Phoenix
Our office is at 15215 S 48th St Ste 180 in the Ahwatukee Foothills area of Phoenix, near the I-10 and Loop 202 interchange. That matters more than it sounds, because the first month of an Ortho-K program involves several short follow-up visits and a long drive turns a simple check into a chore.
We see patients from Phoenix, Ahwatukee, Chandler, Tempe, Mesa, Gilbert, and Scottsdale. Hours are Monday to Friday, 9:00 AM to 5:00 PM. Call (480) 706-3937 or schedule a consultation.
If you are still gathering information, The Process walks through every visit in order, and What to Expect sets out the first weeks week by week.