Orthokeratology - a method for restoring vision, which involves wearing night lenses. This is the method of non-surgical correction. To date, it is considered one of the most effective and simple, so an increasing number of patients of ophthalmology resort to its help.
What are night lenses for vision?
At its core, the usual night lenses are not very different. The main difference is that they are made of a more rigid gas-tight material. During OC therapy, the effect on the cornea and the change in its shape is carried out gradually.
The first night lenses appeared in the sixties. Of course, since then their design has changed greatly and improved. The principle of their operation is based on the fact that, with myopia, the rays of light, bypassing the optical media of the eyes, are focused right in front of the retina. To focus necessarily on the retina, you need to change the shape of the cornea - to make it a little more flat. To do this, you need hard lenses to restore vision. They help to create a new "right" layer of the surface of the cornea.
One of the main distinguishing characteristics of the method is that during the day, the patient does not need any corrective optics. But for orthokeratological principles to work, night lenses should be worn regularly or at least through the night. If you abandon them ahead of time, then within three days the cornea will return to its initial state.
The effect of using refractive therapy - night vision correction with night lenses
According to statistics, orthokeratological lenses can correct myopia in the range from -1.5 to -4 diopters. There were cases when the method also helped patients with myopia in -5 and -6 diopters. But so far they are not so often.
The maximum changes are observed immediately after the first application of lenses. At this point, a correction of approximately 75% of the vision occurs. But full recovery will only happen after 7-10 nights. During treatment in the afternoon, when the patient is not in the lenses, the effect may slightly decrease. This phenomenon is normal.
The advantages of lenses that wear overnight to restore vision:
- Versatility. They have no age restrictions. And this means that they can be used by children who are not suitable for laser correction.
- Security. Under OK lenses, the cornea does not feel a lack of oxygen, as happens in the case of daylight. And even nocturnal hypoxia, which increases under closed eyelids, is fully compensated by day.
- Hypoallergenicity. Orthokeratological lenses do not cause allergies, conjunctivitis, keratitis . In addition, they can safely use any makeup. The main thing to wash it off at night.
- Long-term. Night lenses to restore vision have a long shelf life. And with proper care, they will not have to be changed.
And more: these lenses have no professional limitations, they do not have to be removed every time during sports or swimming. They are suitable even for those people who feel uncomfortable in ordinary lenses.
Contraindications to the use of night lenses to restore vision
With contra-indications it is necessary to come across infrequently, but they are:
- Orthokeratological lenses can not be worn in patients with inflammatory diseases on the eyes and eyelids.
- The method can harm those who have scars in the central zone of the cornea.
- It is undesirable to use lenses in severe dry eye syndrome.
- For the time of illness, which is accompanied by fever and a runny nose, wearing lenses should be discontinued.