Unfortunately, the young eye with its natural accommodative capacity cannot be restored even with the best contact lens or the most advanced surgery. However, there are different approaches that make it possible to see at several distances without reading or progressive glasses and thus improve the quality of life.
There are basically two different approaches to achieving this with contact lenses or eye surgery:
Monovision, also known as the “Goethe View,” is a principle in which one eye is primarily corrected for looking into the distance and the other eye is corrected for proximity. The brain combines both impressions and thus enables extensive independence from glasses or reading glasses. The most common activities of everyday life can therefore be carried out again without glasses.
The difference between the eyes should not exceed 1.5 diopters so as not to impair three-dimensional perception.
In Classic Monovision, both eyes are equipped with monofocal optics. This results in clear vision without loss at a distance, one eye for the distance and the other eye for the middle distance or computer distance. Glasses are often required to comfortably read books or newspapers at close distances.
As with classic monovision, one eye is corrected remotely without compromises. However, the other eye is treated in such a way that an extended depth of focus is created. In this way, a larger visual area can be covered with a minimum loss of visual acuity and contrast at close range. The newspaper can therefore be read without glasses.
Multifocality means that light is refracted to different degrees from different distances and thus several sharp images are created on the retina. This is also known as pseudo-accommodation.
While a monofocal IOL refracts light only from a distance, multifocal IOLs produce several sharp images from different distances on the retina. Through so-called “neural processing,” the brain gets used to reading out the correct image in each case. Opticians are designed in such a way that the near part of the lens is in the center of the lens, because when looking close, the natural pupils constrict. As a result, an addition of +2.5 to +3.0 can be achieved, i.e. the focus for proximity is 40 to 33 cm, also ideal for reading.
There are different types of multifocal IOLs with particular advantages and disadvantages
Surgery is only useful if you are unable to use reading glasses or progressive glasses. This depends primarily on your daily activities.
If there is a lens opacity or cataract, it generally makes sense to think carefully about how you would like to see after the operation and whether and for which activities you want to wear glasses again.
If there is a slight monovision by nature or the test with the glasses or contact lenses works, it makes sense to use this as well.
If Monovision is intolerated, i.e. you feel unwell, have dizziness or need to cover one eye at a time to see near or far, Monovision is not an option for you. In this case, both eyes should be corrected for a distance, i.e. for the distance, the proximity or with multifocal IOLs.
Patients who already naturally have different eyes do not need to simulate monovision with contact lenses.
For all other patients, it is important to try out monovision either with glasses or, better yet, with contact lenses.
Basically, the higher the level of suffering, the greater the joy of the result after the operation. As a result, patients who exercise a lot or pursue hobbies for which glasses are particularly annoying are most suitable for presbyopia treatment.
Between 40 and 50 years of age, the natural eye lens still has a reduced ability to accommodate, so it makes sense in this age group to keep the lens and consider laser eye surgery instead. The lens opacity usually occurs later, between 60 and 70 years of age, and can then be corrected with cataract surgery. The existing monovision or monovision with extended depth of focus remains in place after the gray star operation or can be easily adjusted afterwards with the laser.
After fifty, the natural lens is rigid and can no longer accommodate. At this age, there are often fine opacities in the lens tissue, i.e. the first signs of an incipient cataract. In this case, laser eye treatment of the cornea would still be possible, but the correction may change again as the lens opacity progresses. As a result, it makes sense to completely remove the lenses and to implant an artificial IOL (intraocular lens) in their place. This corresponds to the actual cataract operation, which then no longer occurs at a later age.
