Treatment
Orthokeratology (ortho-k)
Clinically reviewed · Last reviewed 2026-06-13
What it is
Ortho-k lenses are firm, gas-permeable contact lenses worn while you sleep. They temporarily flatten the front of the cornea so that light focuses correctly, so you can see clearly during the day without wearing any correction. The effect is reversible and wears off if you stop using the lenses.
What it is used for
Ortho-k has two main uses, both needing careful fitting and monitoring.
- Glasses-free daytime vision for people with short-sightedness
- Slowing the progression of short-sightedness in children (myopia control)
- An option for those unsuitable for or not wanting laser surgery
- Useful for dusty or sporty environments where daytime lenses are awkward
Safety and what to expect
Because the lenses are worn overnight, strict hygiene is essential to reduce the small risk of serious corneal infection. Vision may take a week or two to stabilise, and lenses must be worn regularly to maintain the effect. Ongoing checks with a specialist optometrist are important.
Conditions this can help
Frequently asked questions
Is orthokeratology permanent?
No. The reshaping is temporary and reversible. You need to keep wearing the lenses overnight regularly, as vision gradually returns to its original state if you stop.
Can ortho-k slow short-sightedness in children?
Yes, it is one recognised option for myopia control in children, alongside other methods. A specialist can advise whether it is suitable for your child.
Is overnight lens wear safe?
It is generally safe with careful fitting and strict hygiene, but overnight wear carries a small risk of corneal infection, so good lens care and regular checks are essential.