Cataract is the most common cause for the removal of the natural lens. With cataracts the healthy eye becomes progressively cloudy. Usually this is a natural process occurring with increasing age though.Thus, vision gradually blurs and dims and everything is seen as through a frosted glass pane. Occasionally increased glare sensitivity is reported.
Once the opacification is advanced in such a way that the visual acuity is affected, the natural lens is removed by a safe standard treatment. Cataract surgery is the only effective way of restoring vision and therefore the most common operation worldwide. Nowadays the removal of the natural lens is combined with implantation of an artificial lens, the so called intraocular lens (IOL). In Germany approx. 800.000 interventions of this kind are performed each year.
Besides the most common, age-related reason, cataract can be congenital or caused by injuries or some medication. Treatment of those forms is the same as described above for the age-related cataract.
Today´s surgical methods and biometry techniques, as well as the production of intraocular lenses, have progressed to the extent that correction of preexisting myopia or hyperopia can be accomplished simultaneously with the cataract surgery by choosing the required IOL power for each patient. The previous spectacle power is integrated within the IOL, so that ideally no additional glasses are needed for far distances.
After consultation with the eye specialist it might make sense in cases of high myopia, hyperopia or astigmatism to replace the natural lens by an IOL prior to the occurrence of cataract. This method of ametropia correction is called “Clear Lens Extraction“ .