How are multifocal contact lenses

What are multifocal contact lenses?

Multifocal contact lenses are so-called multifocal lenses that are suitable for people who have age-related farsightedness and a general ametropia that have to be corrected in combination. They are comparable to biofocal glasses, but in contrast to glasses they have the advantage that the user has an unrestricted field of vision due to the missing glasses frame. The multifocal contact lenses are used as hard and soft contact lenses.

With increasing age, the elasticity of the eye lens decreases, which means that the eye can only perceive everything that is close blurred, but everything that is further away can be seen clearly. Medically this problem is called presbyopia. In the past, reading glasses were used for presbyopia, but they have the disadvantage that they have to be put on separately every time something needs to be viewed from close up. With the help of multifocal contact lenses, reading glasses can be replaced and everything is always seen razor-sharp, regardless of whether it is near or far.

Structure of the Air Optix Aqua Multifocal as an example of a varifocal lens

The multifocal contact lenses have several strengths and are ideal for patients who would otherwise need at least two pairs of glasses. Multifocal contact lenses not only eliminate the problem that the person concerned has to constantly carry two glasses with them, they also offer an advantage because they are invisible, the person concerned with contact lenses can enjoy much more freedom of movement, especially during sport, and they cannot see their face change how it happens with a spectacle frame. The multifocal contact lenses are elastic and take on the shape of the eye lens of the wearer, after a short time the affected person does not even notice that he is wearing contact lenses at all. The contact lenses follow every eye movement, regardless of the position of the head or body.

There are two different manufacturing systems for multifocal contact lenses, the alternating and the bivisual system. The alternating system is similar to the biofocal glasses, with which visual disturbances in the near and far range are compensated in parallel.
The strength ranges of these contact lenses for near and far vision are separated from each other, which means that after a certain period of acclimatization a high-contrast image can be seen without an intermediate range, a disadvantage similar to that of biofocal glasses.
The bivisual system makes it possible for the wearer to adapt to the contact lenses after a trial period that cannot be determined beforehand. They always generate a close-up and a wide image at the same time; during the training period, the human brain with its visual perception center learns to perceive the correct, sharp visual image while suppressing the other. The adjustment time for bivisual contact lenses is shorter than that for alternating contact lenses, but not all types of ametropia can be corrected today. For example, bivisual contact lenses are not suitable for driving at night, and even reading for a long time or working on the computer can cause headaches or severe fatigue.

D and N profiles of the Proclear Multifocal

The multifocal Proclear offers a profile for the far-dominant eye and for the near-dominant eye. In this way, the natural inclination of the eyes is realized with larger far and near areas in the lens. Nevertheless, there are both distance and near strengths in each profile.

Multifocal contact lenses only with professional fitting

Basically, wearers of glasses who want to switch to multifocal contact lenses should consult an optician or their ophthalmologist. There are still many patients who cannot tolerate contact lenses, where the eyes are constantly watering and always irritated.
The multifocal contact lenses should always be tested first. The person concerned only wears them by the hour and still has the glasses with them, so that the contact lenses can be removed if they are bothersome or if the eyes water too much.

So-called silicone hydrogel contact lenses have proven to be particularly helpful for contact lens wearers with dry eyes or with problems with the oxygen supply.
These modern contact lenses have a very high DK value, which means a very good oxygen supply.
So far there have been no multifocal contact lenses made on the basis of a silicone hydrogel.
At the beginning of 2009, however, the contact lens manufacturer Ciba Vision introduced the Air Optix Aqua series as the latest product in the Air Optix Aqua series, which was also very young at the time Air Optix Aqua Multifocalin front.
These offer all the advantages of a high-quality silicone hydrogel contact lens and, in addition to compensating for long-distance vision, also have an integrated reading area.

Ciba Vision can only be congratulated on this development and these contact lenses will be a revelation for those who wear multifocal contact lenses. Another contact lens in the multifocal area is eagerly awaited with the Acuvue Oasys for Presbyopia, since the Acuvue Oasys belong to the highest quality contact lenses for "normal" contact lenses.

by Sebastian Haak