Corneal refractive therapy a.k.a. night lenses
Frequently asked questions
It’s absolutely possible to see without glasses or contact lenses! Use night lenses while you sleep and wake up with clear vision, no need for glasses or contact lenses throughout the day. It’s the comfort and safety in you daily routine, active sports and free time activities!
Corneal refractive therapy is also called vision correction with orthokeratology lenses. The method is commonly known to the public by the term “night lenses”. The method is based on changes in the shape of the cornea, achieved by using a special lens during the night while the patient is sleeping. The result is a temporary improvement of vision that lasts about a day, therefore these lenses need to be worn every night. During the night, the special lens forms an accurate corneal imprint, specifically tailored to the each patient’s needs. In the morning contact lenses are removed, while the changes occurred in cornea during the night now allow the beam to focused at the right spot in the retina, providing the patient with adequate visual acuity.
1. What is night lenses, also known as corneal refractive therapy?
Corneal refractive therapy is a special, non-invasive method that changes the shape of the cornea during sleep by reducing the visual disturbances caused by myopia during the day. Special air-permeable solid contact lenses, also called orthokeratology lenses or night lenses, are placed in the eye before going to sleep. During the night, the lenses help to take the necessary corneal shape so that the wearer can see without glasses or contact lenses during the day. In the morning, the lenses are removed and the visual acuity remains stable throughout the day.
2. Is the improvement in vision achieved by corneal refractive therapy a long-lasting one?
No, the visual improvement is only temporary and reversible. If usage of the lenses is discontinued, the cornea returns to its previous state within 72 hours and vision returns to what it used to be.
3. Can orthokeratology lenses, also known as “night lenses”, be used by just about anyone?
No, not by anyone. Orthokeratology lenses are only suitable for persons with minimal or moderate myopia (up to -6,00 diopter) with or without astigmatism (up to -1.75 diopter). These therapeutic lenses are not available for patients with presbyopia who require bifocal vision correction, i.e. two distances.
The lenses can only correct the visual acuity at a distance. However, expert judgment is required to determine the patient's compliance or non-compliance with the use of night lenses, which involves assessing the anatomical parameters of each patient's eye. Hyperopia, or clairvoyance, cannot be corrected with corneal refractive therapy.
4. How long does it take to achieve a good vision with night lenses?
For most patients a rapid visual improvement is seen within the first few days of treatment, and almost anyone achieves complete visual stabilization within 10 to 14 days. When starting to use night lenses, it should be taken into account that initially, especially during the first days, the improvement in visual acuity may be shorter and last only a few hours. With each following night when the lenses are worn, the effect lasts longer and longer during the day, until a lasting effect is finally achieved. There are also cases where patients maintain visual acuity for up to three days after overnight lens application. However, in children and adolescents whose eyes are still developing, the night lenses should be worn every night, even if the vision remains clear for several days.
5. What to expect in time period between starting to use the night lenses (when the acuity of vision is not yet optimal) and the moment when the vision becomes stable.
It is important to note that from the moment the therapy is started until the moment the optimum acuity of vision is obtained, glasses or contact lenses previously used might not be optimal anymore. Possible solutions include use of the night lenses during the day, for example, when taking a nap, or to choose soft one-day contact lenses.
6. Are there any risks associated with the use of night lenses?
The use of night lenses, like any other contact lenses, may involve some risks, but they are considered to be minimal. Above all, there is a risk of infection if the lenses are not properly maintained and the required hygiene conditions are not met.
7. Is it possible to see through the night lenses if they are intended for use during sleep?
Yes. One of the great features of night lenses is that if patient wakes up in the middle of the night, it’s perfectly possible to move around freely and see everything that is going on. The lenses are designed in such a way as to allow to see through them.
8. How often do you need to change the night lenses?
The manufacturer's recommended due date of night lenses is one year if properly taken care of and worn properly.
9. What is the proper care for night lenses?
When getting up in the morning, the night lenses should be placed in their dedicated storage container and filled with a special peroxide liquid to which a special disinfectant tablet is added. Then shake it thoroughly to begin the disinfection process. During the day, the lenses are cleaned and disinfected with liquid so that they can be safely reinserted by the patient in the evening.
10. Is Corneal Refractive Therapy i.e. wearing of night lenses painful?
The use of night lenses does not cause any pain and no physical changes in the cornea are apparent, only visual improvement is perceptible
11. Is there an age limit for using night lenses?
No, there is no age limit. It is believed that night lenses can be used as soon as the child is sufficiently responsible to be able to wear contact lenses on their own or with the supervision of their parents and to take care of their hygiene. The use of night lenses is a great option for children and adolescents who are active in sports or other activities that require good vision without glasses or contact lenses. Night lenses are also suitable for adults and seniors who, for various reasons, are unwilling or unable to use other types of vision correction.
12. Is it difficult to insert and remove the night lenses?
Night lenses are no more difficult to insert or remove than any other contact lenses. In addition, various aids are available, such as moisturizing drops, which improve the mobility of the lenses in the eye and facilitate the insertion and removal of the lenses, as well as a special aid for the removal of the lenses.
13. Can night lenses also be used by patients suffering from dry eye syndrome?
Only an ophthalmologist or optometrist can determine the suitability of a particular patient for the use of night lenses. Generally, patients with signs and symptoms of dry eye syndrome may wear night contact lenses and will not experience discomfort when using them. Due to the fact that night lenses are used during sleep, tear evaporation is reduced, so night vision correction may even be more appropriate for patients with dry eye syndrome.
14. I used to wear contact lenses, but stopped due to discomfort – can night lenses still be suitable for me?
Night lenses are used when the patient is asleep, therefore significantly reducing the inconvenience and discomfort associated with wearing contact lenses, so night lenses are also suitable for people who experience discomfort when using normal contact lenses.
15. I have astigmatism - are night lenses suitable for me?
Night lenses are designed to correct astigmatism up to -1.75 dioptres. Each patient's eye and vision health are individually evaluated in the clinic to determine the appropriateness of the chosen type of vision correction.
The procedure for providing the service at the Latvian American Eye Center
1. The patient is invited for a visit at the optometrist to determine the patient's eligibility for corneal refractive therapy i.e. night lenses. If the patient's eye parameters and vision characteristics turn out to be suitable for the use of night lenses, the patient is invited to a first night lens visit, duration of which is about 1.5 hours.
2. During the patient's first visit about the night lenses, all necessary diagnostic examinations are performed, enabling the clinic to select a suitable set of night lenses for the patient. During the visit, the patient is informed about the use of night lenses, care, risks associated with the use of contact lenses, the schedule of future visits, etc.
3. The next morning patient is asked to return to the clinic for a doctor or optometrist to evaluate the effects of the lens and changes in corneal shape, and to discuss how the patient feels, and to offer further guidance.
4. A follow-up visit is scheduled at the third day of wearing lenses, at which time a full diagnostic examinations are repeated to assess changes in corneal shape, improvement in visual acuity, and to have a general discussion of the patient's experience with night lenses.
5. Patient is kindly asked to return to clinic for regular follow-up visits at 1 week, 1 month, 3 months and 6 months
6. The price of visits includes 2 additional visits, which can be used by the patient if necessary or by an appointment.