A clouding of the eye lens – referred to as cataract or congenital cataract – may occur unilaterally or bilaterally, be present at birth or develop during the first years of life.
With bilateral cataract the cause can be one of many, very different clinical profiles: it may be a pure eye disease (such as an inherited cataract). Cataract, however, can also be a partial symptom of a general disease (syndrome), arising in the context of a neurological disorder or a metabolic disease.
A frequent indicator of unilateral cataract is when one eye looks noticeably smaller than the other. Only the total cataract can be seen from the outside – that is, if the entire lens is clouded. The pupil is then no longer black, but appears whitish-greyish. Early surgery must be performed. In neonates congenital cataract must be operated on even during the first few weeks of life (at the latest by the 3rd month of life), so that it does not cause irreversible impairment of visual development.