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Cataract Surgery

What is a cataract? What causes it?

The term cataract, refers to the clouding of the natural lens of the eye. The natural lens is an essential part of the imaging system of the human eye, its function is to focus light rays onto the retina. In its normal, youthful condition, the natural lens of the eye is clear and transparent.

The most common form of cataract is age-related. It is caused by metabolic disorders of the lens, which begin in people over 50.

Other causes of lens clouding are certain diseases, such as diabetes, rheumatism, short-sightedness, etc. Injuries, inflammation of the eye or long-term treatment with certain drugs are also known to be the cause or accelerating factor.

There is also congenital opacity of the lens, which occurs either as a hereditary condition in some families or as a consequence of a pregnancy.

Symptoms of cataracts

Typical symptoms caused by cataracts are blurred vision despite correction with glasses, poor contrast vision, high sensitivity to glare, frequent changes in glasses prescription from the age of 60 on, even the development of reading ability without glasses, where reading glasses were previously always necessary.

Furthermore, progressive visual deterioration which can no longer be corrected with glasses may lead to insecurity during normal activities such as reading, driving a car (initially in the dark, later also during the day), walking on stairs, etc. Significant visual impairment can occur in advanced cases.

How quickly a cataract develops is difficult to predict. The visual problems may vary, but the tendency is always to worsen.

How are cataracts treated? The cataract operation

The only effective and definitive treatment known so far is cataract surgery, which means the replacement of the cloudy lens with a new artificial lens. Neither medicines nor alternative remedies such as homeopathy, acupuncture etc. have proven healing.

In cataract surgery, a small incision (approx. 1.8 mm) is made at the edge of the cornea. The cloudy, hardened lens core is liquefied and suctioned with a highly efficient ultrasound device (so-called phacoemulsification), while the lens capsule is preserved.

For soft lenses, a laser can also be used. Instead of the removed cataract lens, an artificial lens made of high-quality medical plastic (intraocular lens (IOL)) is inserted, which restores the transparency and function of the original lens.

The very small, self-sealing incisions do not require sutures enable fast visual rehabilitation within a few days after the operation, provided there were no other eye diseases additionally to cataracts.

In rare cases, a weakness of the lens capsule or the lens suspension apparatus may be found, which could make the insertion of a standard lens difficult or impossible. In these cases, a lens with an alternative fixation system must be inserted.

As a rule, the visual performance will be equally good.

When should a cataract be operated on?

As a general rule, surgery is recommended when the patient’s vision is no longer sufficient for daily requirements and when the patient is ready for surgery.

A cataract that has existed for a very long time is often accompanied by increased lens hardness, which can make the operation more difficult and lead to complications.

Drivers should schedule the operation earlier to ensure that they do not fall below the minimum legal requirements for vision.

How should I prepare for the operation?

During the pre-operative examination a few days before the operation, a particularly precise measurement of the eye – a so-called biometry with a laser interferometer – is carried out. In addition, the retina and cornea are examined, with the aim of ruling out accompanying problems and allowing a particularly accurate prognosis of vision. With all data, the ideal type and strength of the intraocular lens can be determined for each individual patient.

Additionally, a general health examination including blood count and ECG is also necessary. These examinations are usually carried out by the patient’s general practitioner, who certifies that the patient is fit for surgery. At our centre, the anesthetists team is responsible for this. On request, the general examination can be carried out by them.

Drugs for diabetes, blood thinning, cardiovascular and prostate diseases require a special consultation before the operation.

A few days before the operation, pre-treatment with antibiotic eye drops is necessary; these drops will be prescribed in good time.

As a rule, only one eye is operated per session; the second eye may follow a few days after the first. This procedure minimizes risks.

All details, as well as the type of anesthesia and the type of lens to be implanted are discussed in detail with our team during the explanatory consultation prior to the operation.

What does the operation day look like?

At home: Please shower and wash your hair on the day of the operation. Wear comfortable (wide) clothing and please do not wear make-up, hair clips or jewellery. Do not eat anything for at least 6 hours before the operation, i.e. breakfast is not necessary on the morning of the operation. However, usual medication (heart and blood pressure) should be taken, except insulin or diabetes tablets. You can eat again immediately after the operation.

In the operating theatre: On arrival at the clinic, drops are administered to prepare the pupil. In the changing room you will remove your clothes and put on a sterile pyjama. Sedation and local anaesthesia of the eye will follow, and finally the operation itself, which takes between 15 and 20 minutes.


The operated eye will be covered with an eye dressing after the operation and a recovery time of about 20 minutes will be allowed, before the patient can be picked up.

On the day of the operation the patients are not allowed to drive themselves! On the day after the operation, a check-up at our clinic is necessary. The dressing is then removed, the eye is examined, further medical treatment is prescribed , instructions are given and following check-up appointments are made.

Important rules to avoid complications

  • Never press or rub your operated eye. The resistance of the eye is reduced after the operation. The incision may open in case of firm pressure or injury. Avoid sleeping on the side of your operated eye for the first 1-2 nights.
  • Water and soap must be prevented from getting into the operated eye at first, so please make sure to keep your eyes closed and your head tilted far back when showering and washing your hair.
  • Watching television and reading is generally possible – even shortly after the operation – but you should expect more or less blurred vision in the first few days.
  • Avoid heavy physical activity in the early days. You can move normally, even bend down. You should avoid sports such as swimming, diving, cycling or going to the sauna until the eye doctor allows you to do so again.
  • You can expect to be more sensitive to light in the beginning. Sunglasses are a good protection, also against dust and in bad weather conditions.
  • Your ability to work and fitness to drive depend on the development of your visual acuity after the operation. Their visual performance must meet the minimum requirements for road traffic. Any new glasses can only be determined a few weeks after the operation.
  • Very important: take the medication prescribed by your ophthalmologist and keep the agreed examination appointments.

Recommendations for choosing an Intraocular Lens (IOL)

Modern ophthalmic surgery not only enables gentle and safe cataract surgery, but also the fine tuning of vision according to the individual needs of the patient. A prerequisite for this is the right choice of IOL.

All lenses implanted by us are manufactured by various worldwide recognised manufacturers (Carl Zeiss Meditec, Johnson&Johnson, Alcon, Rayner etc.) and have the following standard features:

  • excellent material quality with a lifetime guarantee after implantation.
  • aspherical optics: the latest optical technology (wavefront) for the correction of spherical and chromatic aberrations and for maximum light transmission. The aim is to improve contrast and twilight vision.
  • UV light filter to protect the healthy retina.

Classic Monofocal Lenses (single vision lenses)

They have a fixed focal length, which usually allows you to see at a distance, or alternatively close up, but not both at the same time.

After the operation you can expect to wear glasses in everyday life.

They are a good choice for patients who do not have any special visual requirements and are satisfied with glasses after the operation.

They are inexpensive and are paid for by all health insurance companies.

Mmultifocal Intraocular Lenses (MIOL)

Multifocal lenses are multifocal lenses with additional focal lengths that allow vision at multiple distances. In everyday life there is a great (or even complete) independence from glasses. Patients with multifocal lenses are able to drive a car, go shopping, read a restaurant menu, etc. in good lighting conditions without glasses. Multifocal lenses can therefore correct not only cataracts but also presbyopia.

But not all patients tolerate multifocal IOLs equally well. Due to the optical design of these lenses, subjectively disturbing light phenomena such as halos around light sources can occur, especially at night, which are generally tolerable and decrease over time.

MIOLs are generally not suitable for patients with additional eye diseases, e.g. corneal diseases, macular degeneration, advanced glaucoma, etc.

Multifocal lenses were developed to optimise optical performance according to individual needs by eliminating (or greatly reducing) the need for glasses after surgery. Unfortunately, some health insurance companies generally still consider this additional function as “cosmetic” and often reject the extra costs associated with these IOLs. They are therefore only available to patients as an optional service with private co-payment.

Multifocal Lenses for the remote and middle surrounding areas (Bifocal or EDOF Lenses)

EDOF lenses (EDOF= Extended-Depth-of-Focus) have a new type of optics with an extended focus range (depth of field). They enable an active lifestyle with a high degree of independence from glasses for most of the tasks of daily life.


  • Sharp vision in the distance and at medium distances (approx. 60-70 cm, corresponding to one arm length) without visual aids, i.e.: sports, social contacts, cleaning, cooking, shopping and other typical housework and gardening, computer work, television, driving a car etc.
  • Less perception of halos and glare in the dark than with trifocal lenses, which is especially important when driving in the dark.


  • To read small print and for precision work at short distances, reading glasses are required. However, these glasses usually stay at home and do not have to be worn all the time.

Multifocal Lenses for all areas of vision (Trifocal Lenses)

Trifocal lenses have the most powerful optics among intraocular lenses.


In good light, they offer continuous vision at all distances: far, medium and close (distance 33cm). With trifocal lenses, almost all activities, such as watching television, driving, shopping, sports, including reading small print, are possible – without glasses or contact lenses. The chance of no longer being dependent on glasses is over 90%.


Overall longer and individually different habituation time to the function of the lenses than with other types of lenses. Particularly immediately after the operation and for up to 3-6 months at night, disturbing light phenomena such as halos (halos around light sources) can occur. Although these are generally tolerable and decrease over time, they can make it difficult to drive at night.

Additional astigmatism correction: Toric Lenses

Toric lenses were developed to correct high corneal astigmatism (astigmatism) in order to keep the necessary correction of glasses after lens surgery as low as possible. The astigmatism-correcting function is compatible with any optics, whether monofocal or multifocal.

Additional blue light filter

IOLs with an additional blue light filter were developed to provide further protection of the retina against blue light. This is essential in cases of pre-existing retinal diseases, such as age-related macular degeneration.

Questions to assist in decision-making

After the operation, would you be interested above all in…

  • Seeing far away without glasses (driving, tennis, golf, television)? – YES / NO
  • Medium distance vision without glasses (computer, iPad, price tags, cooking)? – YES / NO
  • Seeing without glasses for close-ups (books, newspapers, detailed handwork)? – YES / NO
  • All at the same time, i.e. the highest possible independence from glasses? – YES / NO

Do you drive a car, also often at night and/or do you practice sports that require quick reactions (tennis) and where high visual performance is of great help? – YES / NO

If you want to reduce or largely eliminate your dependence on glasses and / or want better visual performance after lens surgery / cataract surgery, this can be achieved with a so-called “premium” intraocular lens. Such implants are not covered by most health insurance companies and require a private co-payment. Would you still accept this possibility? – YES / NO

If you answered “YES” to the majority of the answers, a multifocal IOL can be a great help in achieving your visual goals.

If you answered “NO” to most of the answers, a standard or classic IOL is the right choice.

Please let us know your wishes in the clarification discussion before the operation.

Performance spectrum of different lenses

Television +++ +++ +++
Golf +++ +++ +++
Suitability to drive by day +++ +++ +++
Fitness to drive at night +++ ++(+) +(+)
Computer without glasses +++ +++
Reading newspapers without glasses +++ +++
Tablet without glasses +++ +++
Mobile phone without glasses +++ +++
Long book reading without glasses + ++(+)
Medication leaflet without glasses ++(+)
Needle threading without glasses ++(+)
Glasses necessary for distance (+)
Glasses necessary for the middle range (60-70cm) +++
Glasses necessary for close range (30-40 cm) +++ + (-)
Glare or halos at night (+) + ++ bis +++
Performance depends on good lighting (+) ++ +++
Cost + ++ +++