Cataracts are characterised by a clouding of the lens, which is usually clear and transparent. This is a natural lens located behind the iris, which allows beams of light to converge on the retina. When the lens loses its transparency, light can no longer penetrate to the back of the eye, gradually causing decreased vision as well as blurred vision.
Often natural, cataracts develop with age and can affect anyone. Sometimes, those suffering from acute myopia, glaucoma or age-related macular degeneration are at a greater risk of developing cataracts. In some cases, cataracts may also be present from birth or may be caused by trauma or the use of some medications.
Without care, cataracts will not improve and they may lead to a slow deterioration in vision. With surgical treatment, and if no other eye disease is present, an improvement in vision can be expected.
Types of cataract
- Senile cataract: These are the most common type of cataract. The clouding of the lens is simply due to the normal ageing process.
- Traumatic cataract: These result from a contusion, an impact, a wound, etc.
- Secondary cataract: This type of cataract may be caused by:
- some diseases, such as diabetes
- some medications, such as cortisone
- some vision problems, such as acute myopia, glaucoma or a detached retina
Cataracts are treated by surgical intervention, at an outpatient clinic in the vast majority of cases, under local anaesthetic. Cataract surgery is the most commonly performed operation in medicine.
A cataract operation involves replacing the clouded lens with a transparent artificial lens. To do this, the ophthalmologist inserts an ultrasound probe into the cornea, without cutting it, in order to break up the lens. This is then replaced with an artificial intraocular lens. When positioning the new lens, the surgeon takes the opportunity to correct the refractive error, so that the patient no longer needs to wear glasses.
Reduced visual acuity, halos around sources of light, reduced ability to perceive contrast, dazzling by bright lights