What is a cataract?
A cataract is the loss of transparency of the crystalline lens, the eye’s natural lens located behind the pupil. Rays of light pass through this lens to reach the retina, where images are formed. If the lens becomes less transparent and obstructs the passage of light to the retina, the patient suffers from a progressive loss of vision.
An eye without a cataract. The lens is transparent.
An eye with a cataract. The lens is opaque.
What causes it?
As people get older, the crystalline lens becomes more opaque. Aging is the main cause of cataracts.
There are other factors unrelated to age, however, cataracts can be caused by genetic predisposition, trauma, diseases of the eye or the organism (e.g. diabetes) or the consumption of certain drugs. In some cases, a cataract is congenital, i.e. present from birth.
How can it be prevented?
Cataracts cannot be prevented, but they can be detected by eye check-ups. It is advisable to see an ophthalmologist, especially after the age of 45, to detect the possible existence of a cataract, its type, size and location, and to determine whether surgery is required and when it should be carried out.
Depending on the size and location of opaque areas on the crystalline lens, the patient may not notice the development of a cataract.
These are some of the most common symptoms:
- Blurred and sometimes double vision when a cataract is forming
- Photophobia (sensitivity to light)
- Better vision on cloudy days than on sunny days
- Glasses are no longer required for near vision
- Driving at night becomes more difficult
- Prescription glasses need to be changed more frequently
- After the age of 50, myopia may worsen, or alternatively, eyesight may inexplicably improve. This occurs because the cataract can cause some changes to the lens, creating a magnifying glass effect
Simulation of the vision of a healthy eye.
Simulation of the vision of an eye with a cataract.
Surgery is necessary to treat cataracts. The most common procedure is phacoemulsification, which consists of emulsifying the cataract and aspirating it. An artificial intraocular lens is then fitted to replace the content of the opaque lens. The choice of lens depends on each patient’s visual characteristics.
The procedure is quick, painless, low risk in terms of anaesthesia and easy to recover from.
Although it produces good results, it is important to remember that it does involve surgery and is therefore not without risk. Complications resulting from poor cataract surgery are the main cause of opacity in the cornea, glaucoma, retinal detachment and other conditions.
To minimise the risks of surgery, patients should put themselves in expert hands to ensure the most appropriate technique is used.