What is a cataract?

A cataract (alternative name: lens opacity) is a cloudy area or opacity in the usually crystalline eye lens. The opacity of the natural lens is mostly not perceived in its initial phase and gradually increases with time. This increase of the opacity of the lens comes along with a decrease of vision.     
Because of this, incident beams can no longer be focused adequately onto the retina. The light is then rather dispersed and absorbed.

The onset of cataract

Cataract is not a disease but rather a natural development of advancing age, induced by a decelerated metabolism. The adult cataract usually develops after the age of 60 or 65 and is by far the most common reason for cataract surgery. Eye injuries, medications or diabetes, however, can also lead to cataract formation in younger people.

Human eye anatomy

The human eye basically resembles a camera. The lens is located right behind the so-called pupil, a small aperture of the iris. It refracts and focuses the incoming light beams and projects these onto the retina. The retina and the optic nerve “transport” the image signals to the visual cortex, an area responsible for vision in the human brain (see figure).

How is a cataract diagnosed?

At first, the subjectively sensed vision seems weakened at low light. It may seem to you as if the glasses are not adequate anymore. The ophthalmologist then detects the cataract with painless methods (slit lamp and microscope) and gives advice on further procedures.

How is a cataract treated?

Since the opacity is irreversible, your vision can only be improved through cataract surgery. Surgery is reasonable if your vision does not seem sufficient for your everyday life, meaning for example if problems are perceived at your job or during traffic. The ideal timing for a treatment is best determined with your ophthalmologist.