Presbyopia is the technical term for presbyopia. The term comes from the Greek and means "presbys" = old. The term already implies that presbyopia is a natural ageing process of the eye.
For the person affected, presbyopia becomes noticeable when the ability to read at close range without spectacle correction decreases. This happens from around the age of 45. Initially, presbyopia begins with an increasing reading distance because focusing at close range no longer works well.
The ageing process takes place in the natural lens of the eye. The lens in the still-youthful eye is able to change its shape.
It does this by becoming more curved and then flatter again. As a result, it changes its refractive power and can focus on objects in the distance and close up. This process is also called accommodation. Accommodation is triggered by the ring muscle in the eye.
The muscle contraction loosens the zonular fibers on which the lens is suspended in the eye. This gives the lens, which is under tension due to its elasticity, room to curl more.
This allows it to focus on objects close up because the refractive power of the lens increases. In the course of life, the lens loses its elasticity so that the ability to accommodate decreases. According to experts, the muscle strength of the circular muscle and the consistency of the zonular fibers remain unchanged into old age.
Presbyopia leads to increased reading distance from the age of 40 and does not require sharp near vision without reading glasses.
Due to the typical development, which affects everyone, and due to age, everyone can make the diagnosis themselves. To confirm the diagnosis and rule out other eye diseases, such as glaucoma, a visit to the ophthalmologist is always advisable in old age.
The treatment ofchoice for presbyopia is to wear reading glasses. If the person concerned is not sighted at a distance (e.g. long-sighted or short-sighted), multi-focal glasses may be useful. These correct the near vision differently to the distance vision, so there is no need to switch between several pairs of glasses.
A patient who is primarily short-sighted with presbyopia will be able to see near without glasses. This is possible because the entire optical system of the short-sighted person has the focal point at near. The image is therefore sharp there even without accommodation.
If the impairment caused by reading glasses is very severe, it is generally possible to treat presbyopia surgically. However, when considering surgical treatment options, you should bear in mind that complete restoration of accommodation is not possible. Surgery is basically a compromise. It is a pseudo-accommodation.
In principle, operations to correct presbyopia are possible on the cornea or the lens; some methods work with a laser. In principle, the methods work with a surface design that generates several focal points simultaneously. Monovision is also possible. In this case, doctors focus one eye on distance vision and the other on near vision.

Figure 1: Example of shaping the corneal surface with a laser to correct presbyopia (source: Schwind)
If the natural lenses are replaced with artificial lenses, special lenses are available to correct presbyopia:
- Multifocal lenses
- Accommodative artificial lenses
- Multifocal lenses for the treatment of presbyopia
Multifocal lenses are lenses that generate several focal points simultaneously. They are currently the most reliable method of correcting presbyopia with independence from spectacles for patients at distance and near.
With these lenses, the focus is on improving quality of life, but there is no optical benefit from multifocal lenses.
On the contrary, optical side effects such as glare or halos are more frequent and more pronounced than with single-vision lenses. This is due to the optical principles used to create multiple focal points.
Figure 2: Example of a multifocal artificial lens in the eye after removal of the natural lens.

Figure 2: Example of a multifocal artificial lens in the eye after removal of the natural lens.
Strictly speaking, these lenses are pseudo-accommodative lenses, as artificial lenses cannot imitate natural accommodation. The mechanisms are too complex for this.
The principle on which the lenses are based is the shift principle. This causes the optics of the lens in the eye to make a slight forward movement during accommodation. This shifts the focal point.
The principle is limited, as an artificial lens with normal refractive power requires too much forward movement for sufficient accommodation. This is not anatomically feasible, as the artificial lens would then have to move in front of the iris. For this reason, there is insufficient data in the literature to prove that such lenses are independent of spectacles.
Presbyopia is a natural ageing process. A cure is not possible. Accordingly, treatment with medication is also not possible.