---
title: "Orthokeratology (ortho-k) | Eye Health Guide"
description: "How orthokeratology lenses reshape the cornea overnight for glasses-free days, their use in slowing short-sightedness in children, and safety."
url: https://eyehealthguide.org/treatments/orthokeratology/
source: Eye Health Guide
licence: "General information only. Cite the URL and the named medical reviewer."
---

Treatment

# Orthokeratology (ortho-k)

Medical reviewer [Mr Mohamed Mohyudin](https://eyehealthguide.org/reviewers/mohamed-mohyudin/)· Last recorded site review July 6, 2026

### About this review

This page inherits the site’s previous review record. A separate, current article sign-off has not yet been recorded.

[How review works](https://eyehealthguide.org/reviewers/) · [Official biography & credentials](https://mohamedmohyudin.co.uk/author/mohamed-mohyudin/)

Quick answer

Orthokeratology, or ortho-k, uses specially fitted rigid contact lenses worn overnight to gently reshape the cornea, giving clearer vision during the day without glasses or lenses. It is used for short-sightedness and is also one option to help slow its progression in children.

### On this page ⌄

1. What it is
2. What it is used for
3. Safety and what to expect
4. Conditions this can help
5. Frequently asked questions

## 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.

Your next step

## Take this to your appointment

Write down what has changed, when it started, your current medicines and the questions you want answered. Take these to your eye-care appointment.

Sudden loss of sight, severe eye pain or a dark curtain across vision needs immediate assessment. Do not wait to complete a worksheet.

## Sources for this information

These references support the information on this page. Follow the linked source for its full context.

- [College of Optometrists - Orthokeratology](https://lookafteryoureyes.org/eye-wear/orthokeratology/)