A cataract is a cloudiness in the focusing lens inside the eye. When the lens becomes opaque, the amount of light that passes through it is reduced and scattered, and the image cannot be correctly focused on the retina at the back of the eye, leading to blurred vision. The eyes may be more sensitive to glare and light, and colours may seem faded or yellowed. Double vision may also occur.
Although the exact mechanism by which cataracts develop is not understood, some of the associated factors which are strongly related to cataracts include:
Age: the older a person becomes the more likely it is that one will develop cataracts. In fact, some degree of cataract is found in most patients over the age of 70 or 80. It is not uncommon to find some degree of cataract in patients in their 50s and 60s.
Sunlight exposure (UVB): there is a strong relationship between the amount of UVB exposure during one’s lifetime and the later development of cataracts.
Other diseases: The incidence of cataracts is higher in countries where malnutrition and general gastro-intestinal diseases (diarrhoea and vomiting) are more common.
It is important to understand that a cataract almost never causes damage inside the eye and just blocks out vision progressively as it becomes cloudier. However, whatever vision is going to return with removal of the cataract today will be the same in five years time unless some new disease develops in the eye. This means that the removal of a cataract is a very elective procedure as the cataract does not cause irreversible blindness in an eye. The time to remove a cataract is when it is interfering with vision sufficiently that the patient is no longer able to perform and function as they would like.
Although cataract removal is an extremely successful surgical procedure, like any surgical procedure it does come with associated risks of complications and problems. Therefore it is not a surgery to be undertaken lightly and the patient must find an ophthalmologist in whom they have trust and confidence to perform this procedure.
The removal of the cataract is almost now universally associated with a replacement “plastic” lens insertion at the time of the cataract removal to minimize the need for thicker glasses.