When a cataract begins to develop, vision is obscured and clouded; the patient will face difficulties when reading, watching television, identifying objects positioned at a moderate distance from the eyes, driving, particularly at night (due to glare) etc…
A cataract develops with age and can be described as the progressive opacification of the crystalline, the eye’s natural lens.
To explain the phenomenon better, let’s try and compare the eye to a photographic camera.
Both the eye and the photographic camera contain lenses that focus images: the lens of a photographic camera focuses and transmits the image to a film, just as the cornea and the crystalline in the eye focus the image on the retina.
If the lens of the photographic camera is partially or totally opaque, the amount of light that passes through it will be insufficient and there will be a poor representation of the image on the film; consequently, the photographs will be poor quality; in the same way, when the crystalline is opaque, the light will be partially blocked and the resulting images will be opaque, clouded and indistinct.
The probability of developing cataract therefore increases as the patient ages and the phenomenon is observed more frequently in the over-60s.
People affected by myopia are more likely to develop a cataract and it may appear at a greater frequency in this group of patients.
However, a cataract does not exclusively affect the elderly.
Cataract development may be congenital; it may be present from birth or may have been caused by external factors, such as a cataract caused by prolonged exposure to intense heat or by local and generalized trauma.
Other frequent and precocious cataracts are those that develop in association with severe myopia and those induced by local or systemic drug administration (cataract caused by cortisone).
The symptoms of cataract
On occasion, a cataract will develop in just a few months; however, more frequently, the process takes years; sometimes, it will interfere with sight from the outset, or it may be undetected months without causing any discomfort.
These symptoms of decreased or modified sight quality are important signals that should not be ignored: if the patient is concerned about the changes to his/her sight, s/he should consult an eye specialist.
As the initial changes associated with a cataract can be easily confused with symptoms associated with other medical problems, only a specialist eye doctor has the ability to diagnose a cataract and recommend the appropriate treatment.
Once a cataract has been diagnosed, the patient must schedule periodic eye examinations: these visits will allow the patient and the eye doctor to determine the stage of the cataract’s development and therefore determine the appropriate moment for surgery.
Initially a cataract will develop in one eye but will almost always develop in the other at a later stage.
The decision to proceed to surgery depends on many factors.
Surgery will usually be required when eyesight deteriorates because the cataract obstructs the passage of light and interferes with sight. Due to the fact that even a minor deterioration in sight is unacceptable for the majority of patients, surgeons will normally decide to operate as soon as the initial symptoms appear.
However, despite the fact that a precocious procedure is usually more straightforward and is associated with a number of other advantages, many patients prefer to wait.
In any case, surgery should not be delayed indefinitely: in the long-term, a cataract can damage the eye and as it further reduces the sight capacity, there is an increased risk of falling, particularly where elderly patients are concerned.
Surgery should be performed before the cataract greatly reduces sight.
Normally when a patient is affected by cataract, the surgeon will operate one eye at a time; the first eye to be operated will be the eye with more advanced opacity and this will allow the patient to use the other eye in the period immediately after surgery; a few days or weeks later, the second eye should be operated. Vision will improve considerably when both eyes have been operated: depth perception will increase, the evaluation of distance and color perception will improve; reading will be easier and visual balance will be redressed.