Cataract (Katarakt)

What is a cataract?

Cataracts are the clouding of the crystalline lens of the eye, which occurs with age, especially in older people, but can also occur in younger people and even in children. The lens lies behind the iris and, together with the cornea, forms an optical system that receives the image in a similar way to a camera. It has the task of focusing the incoming light and projecting it onto the retina.

The lens of the eye consists of crystalline proteins and water, which, however, lose transparency over time and can become clogged. This leads to clouding of the lens and impairment of vision, which manifests itself in the form of a “veil in the eye”. Symptoms include progressive cloudiness that slowly changes vision, colors become duller and daylight becomes more dazzling. Reading is only possible in strong light.

Treatment usually consists of surgery to replace the clouded lens with an artificial lens. This is done using an ultrasound probe, which emulsifies the lens and is then suctioned off. This procedure is usually performed on an outpatient basis and after only a very small incision, which speeds healing. There are also other surgical methods that can be used depending on the type of cataract, such as the use of lasers.

What will replace the removed lens?

The removed natural lens in the eye must be replaced with an artificial lens to restore or improve vision. This artificial lens is called an intraocular lens or implant and is usually made of a well-tolerated material such as acrylic or hydrogel. It is either inserted into the natural lens capsule sac or, in the event of complications, placed in the anterior chamber of the eye in front of the iris. There are different types of intraocular lenses that come in different shapes and sizes and are secured with elastic straps. They are designed for permanent use in the eye and do not require maintenance. Some lenses also have a filter that blocks a large part of the harmful ultraviolet rays. The best lens is selected individually for each patient based on the exact curvature of the cornea and the length of the eyeball.

Since when is cataract surgery known?

The idea of using an artificial lens to replace the eye’s natural lens dates back to the late 18th century. However, at that time the technology was not yet advanced enough to enable successful implementation. The development of modern cataract surgery did not begin until World War II. Observations that soldiers who had fragments of a certain plastic material in their eyes showed no negative reaction led to the development of lenses made of this material. However, microscopy in surgery was not yet mature, so success remained uncertain. It wasn’t until the 1970s that the techniques evolved and were found to be safe and effective. Today, thousands of intraocular lenses are implanted in an outpatient setting every year. Surgery is recommended when the impairment affects vision, daily life or work, and also affects driving.

When should cataract surgery be performed?

The decision to operate on a cataract should not be made based solely on the presence of the disease. It is important to consider the impact on everyday life and the expected improvement in vision.

What are the chances of success of the surgery?

Today, cataract surgery is a state-of-the-art procedure with a high success rate of over 95%. However, there is always some risk of complications and no surgeon can guarantee absolute success. There are other reasons for vision loss that cannot always be identified before surgery. For example, severe damage to the retina may not improve cataract surgery. However, the ophthalmologist can usually assess beforehand whether there is a high probability that vision will improve after the operation. There are also two important indications that require urgent surgery in exceptional cases: a cataract causing severe inflammation and acute or chronic glaucoma (glaucoma = increased intraocular pressure). As your ophthalmologist, we would like to offer patient-oriented treatment through modern diagnostic methods and expert advice and contribute to improving your quality of life. With high-quality medicine and advanced technology in our practice, we take care of your eyes and do everything we can to keep your vision as good as possible.

Don't wait too long to see an ophthalmologist

Tanja Schmückle Meier


Seit Feb 2024 Teilzeitpensum Seeaugenpraxis Horgen
1998-heute breites Erfahrungsspektrum mit Patienten aller Altersgruppen durch orthoptische, wissenschaftliche sowie administrative Tätigkeiten und Weiterbildungen in verschiedenen Augenarztpraxen in den Kantonen Zug und Zürich sowie am Universitätsspital Zürich
1995-1998 Ausbildung zur Orthoptistin am Kantonsspital St. Gallen
1994 Abitur in München