As the disease progresses, people suffering from cataract increasingly see their environment as if they were looking through a cloudy piece of glass. If the condition is not treated, blindness may be the result.
The number of persons affected by the disease is increasing all over the world. Cataract is relatively easy to treat. The replacement of the cloudy lens with an artificial lens is done on an outpatient basis and is the world's most frequently performed surgery. Almost 90 percent of patients enjoy excellent vision afterwards – many of them without any need for eyeglasses! Here it is essential to select the right artificial lens which requires exact measurement of the length of the eyeball, the corneal radius and the distance between the cornea and the lens. For the past 15 years, ZEISS has offered systems with which doctors can conduct these examinations in a non-contact and therefore painless manner – unlike measurement using ultrasound. The principle of "optical biometry" incorporated in these devices uses the phenomenon of interference, i.e. the superimposition of two light waves where their phase relationship remains constant. To achieve this, a laser is needed as a light source because light waves emitted by a filament bulb change their phase relationship very quickly and randomly.
Produced in Jena to this very day, the "IOLMaster" from ZEISS is one of the most successful ophthalmology products of recent years. After more than 100 million IOL calculations worldwide, the system is now seen internationally as the industry's standard for the exact calculation of artificial lenses for cataract patients.