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What Is Orthokeratology? A Scientific Look at Night-Time Vision Correction

Orthokeratology (or ortho-k) is a non-surgical, reversible method of vision correction that uses specially designed rigid contact lenses to reshape the cornea while you sleep. Upon waking, the lenses are removed and clear vision is maintained throughout the day—no glasses or daytime contact lenses required.

How Does Ortho-K Work?

The front surface of the eye, the cornea, helps focus light onto the retina. In people with myopia (short-sightedness), the cornea is often too steep or the eye too long, causing light to focus in front of the retina. Ortho-k lenses gently flatten the central cornea overnight, temporarily correcting the refractive error.

These lenses are made of highly oxygen-permeable materials and are designed using corneal topography, a 3D mapping of the corneal shape. The reshaping effect typically lasts 24–48 hours, so nightly wear is recommended for consistent results.

Advantages of Orthokeratology

• Freedom from glasses and daytime contacts – ideal for active lifestyles or dusty environments.
• Myopia control – studies show ortho-k can slow the progression of short-sightedness in children by reducing eye elongation.
• Non-invasive and reversible – unlike laser eye surgery, ortho-k can be stopped at any time, and the cornea will return to its original shape.
• Improved visual comfort – no dryness or irritation from wearing lenses during the day.

Risks and Considerations

• Infection (Microbial Keratitis) – overnight lens wear slightly increases the risk, though this is minimised with proper hygiene and follow-up care.
• Discomfort or adaptation period – initial wear can feel foreign until the eye adjusts.
• Temporary blur or halos – may occur during the adaptation phase or with inconsistent lens wear.
• Not suitable for all prescriptions – ortho-k is most effective for low to moderate myopia and certain cases of astigmatism.

Is Ortho-K Right for You?

Orthokeratology is a safe and effective option when properly fitted and monitored by a qualified optometrist. It’s particularly useful for:

• Children and teens with progressive myopia
• Athletes and swimmers
• Adults wanting a surgery-free alternative to LASIK