Myopia affects a growing number of people worldwide. According to the WHO, nearly 50% of the global population could be nearsighted by 2050. In France, more and more children and adults are looking for solutions to avoid wearing glasses or contact lenses during the day. Laser refractive surgery (LASIK, PRK, SMILE) remains an effective and permanent solution, but it is not suitable for everyone. For those who cannot or do not want to have surgery, there is an alternative: night lenses, also known as orthokeratology lenses or Ortho-K. They allow you to enjoy clear vision without glasses or contact lenses throughout the day.
What are night lenses and how do they work?
Definition and principle of orthokeratology
Night lenses belong to a specific category: they are rigid, oxygen-permeable lenses designed to be worn exclusively while sleeping. Their purpose? To temporarily reshape the cornea in order to correct vision problems. During the night, the lens exerts gentle, controlled pressure on the surface of the eye, slightly and reversibly altering its curvature.
Result: upon waking up, after removing the lenses, the cornea retains the shape obtained during the night. Distance vision is clear without glasses or daytime lenses. This effect lasts an average of 24 hours, requiring regular wear every night to maintain results.
Thumbs up: to understand better
Night lenses are like a small "mold" for the eyes. When you sleep with them in, they very slightly flatten and reshape the surface of the eye (a bit like when you sleep on a pillow and wake up with a mark on your face). Thanks to this new shape, light entering the eye is focused better and vision is clear during the day, without glasses or contact lenses. The effect is temporary: it lasts about a day. To continue seeing well, you must therefore put the lenses back in every night.
For which visual disorders?
Ortho-K lenses mainly correct:
– Mild to moderate myopia, generally up to –4 diopters (or even –6 depending on corneal topography).
– Mild astigmatism, in some cases.
– More rarely, mild hyperopia or early presbyopia.
The most common indication concerns children and adolescents whose myopia is progressing, as refractive surgery is contraindicated before vision stabilizes.
Differences from soft lenses and surgery
Unlike soft or hard lenses worn during the day:
– Ortho-K lenses are worn only at night, which avoids the problems of dry eyes associated with wearing them during the day.
– They allow complete freedom during sports, water activities, or work.
– They do not require surgery: the cornea returns to its original shape if nighttime wear is discontinued.
Compared to surgical techniques (LASIK, PRK, SMILE), orthokeratology is 100% reversible. This is an advantage for patients who are still hesitant or ineligible.
What are the benefits of night lenses?
Clear vision without glasses or contact lenses during the day
After wearing your lenses all night, your vision is clear from morning to night. Driving, reading a blackboard in class, working on a screen, or playing sports can all be done without discomfort or dependence on glasses. Professions that require optimal vision without constraints (firefighters, military personnel, pilots, athletes, divers) find this a real advantage.
A non-invasive and reversible alternative
Certaines personnes ne peuvent pas bénéficier d’une chirurgie réfractive (cornée trop fine, myopie non stabilisée, âge < 18 ans) ou appréhendent l’opération. Les lentilles Ortho-K représentent une option sécuritaire et temporaire, qui permet d’attendre la stabilisation de la vue ou de différer une chirurgie définitive.
A slowing effect on myopia in children
Numerous studies show that orthokeratology slows the progression of myopia in children and adolescents. By reshaping the cornea, these lenses influence the axial growth of the eye, which limits the worsening of myopia. This preventive effect is a major argument for parents.
Greater comfort and visual safety
Wearing contact lenses during the day can cause dry eyes, especially in air-conditioned environments or when looking at screens. Ortho-K avoids this problem. In addition, not having anything in your eyes during the day reduces the risk of losing or dislodging your lenses during intense physical activity.
What are the limitations and contraindications?
Eligibility criteria
L’orthokératologie n’est pas adaptée à tous. Pour en bénéficier : myopie légère à modérée (< –4D), cornée saine sans pathologie, bonne hygiène et suivi strict. Un bilan complet est indispensable (topographie, mesures précises, film lacrymal).
Strict maintenance and hygiene
Night lenses require daily discipline: cleaning, disinfection, and regular replacement. Failure to comply increases the risk of infectious keratitis.
Temporary results and dependency
The corrective effect is reversible. If you stop wearing them, your nearsightedness will return within a few days. Regular wear is therefore necessary.
Cost and reimbursement
Ortho-K lenses are more expensive than traditional soft lenses (€400 to €800 per pair). Social Security does not reimburse this treatment, but some mutual insurance companies may offer partial coverage.
Practical tips for effective and safe treatment
To maximize benefits and minimize risks: consult a specialist, follow hygiene and maintenance guidelines, attend check-ups (24 hours, 1 week, 1 month, then every 6 to 12 months), and report any abnormalities.
Conclusion: an innovative and secure solution
Orthokeratology lenses are a modern, non-invasive alternative for adults who are not eligible for surgery and children with rapidly progressing myopia. They offer clear vision without glasses or daytime contact lenses, and are reversible and safe with proper monitoring. However, they require diligence, good hygiene, and professional guidance.
To find out if you are eligible, consult a specialist ophthalmologist: they will assess your situation and offer you a personalized treatment plan.
FAQ – Frequently asked questions about night lenses
Can Ortho-K lenses be used from a young age?
Yes, from age 6-7 under parental supervision and strict monitoring. They are particularly recommended for slowing the progression of myopia.
What happens if I forget to wear them overnight?
Vision remains normal for one day, but may begin to deteriorate thereafter. Regular use is necessary to maintain the effects.
Does it hurt?
No, contact lenses do not cause pain. You may experience slight discomfort during the first few nights while your eyes adjust.
Can Ortho-K be combined with glasses?
Yes, a low prescription in glasses can be used at the end of the day if the effect of the lenses diminishes.
Do Ortho-K lenses pose a risk of infection?
The risk of infectious keratitis is low if hygiene and care instructions are followed and medical follow-up is carried out.
How long does it take for the correction to be effective?
Most patients notice an improvement after the first night, with vision stabilizing within 1 to 2 weeks.
How long does a pair of night lenses last?
On average, a pair lasts 12 to 18 months, provided that the care instructions are followed.
What precautions should I take to protect my eye health?
Use appropriate cleaning products, never rinse lenses with tap water, and consult your specialist regularly.
