Presbyopia: a visual condition determined by the gradual loss of the ability to focus on near objects. It is an absolutely natural and physiological phenomenon which affects all human beings after 45 years of age.
Initially a sense of blurry vision and visual fatigue, followed by increasing difficulty in reading or in other activities that involve near vision, especially in dim light conditions.
Presbyopia is corrected with the use of glasses with lenses that can be: monofocal, bifocal, multifocal or progressive. It is also possible, in selected cases, to correct presbyopia with laser eye surgery (laser techniques) and with cataract surgery, in which multifocal or EDOF intraocular lenses (IOLs) are put in place of the natural crystalline lens.
Presbyopia is a visual condition caused by the gradual loss of the ability to focus on near objects. It is an absolutely natural and physiological phenomenon which affects all human beings after 45 years of age.
The main causes of presbyopia are the progressive decrease of plasticity of the crystalline lens and the reduced functional capacity of the ciliary muscle.
At the beginning, the far-sighted subject will perceive a sense of blurry vision and visual fatigue, especially at night and in dim light conditions, while reading or in other activities that involve near vision.
As presbyopia progresses, the patient will tend to position the book or the newspaper that he/she wants to read further and further away, to try to get it into focus, until an arm's length will not suffice to compensate for the visual impairment.
In short-sighted subjects presbyopia develops later or, at leastoutwardly, does not arise at all, because the short-sighted subjects very often have got used to taking off their glasses for long distance viewing.
In contrast, for the subject affected by hyperopia the process starts before and has a faster evolution since presbyopia is combined with the basic refractive error.
Presbyopia tends to progress from the age of 40 up to the age of 60-65.
Presbyopia is corrected with the use of glasses, which can be of various types:
1) monofocal lenses, which provide the patient with good near vision;
2) bifocal lenses, which provide the patient with both near and far vision (glasses with "lunettes");
3) multifocal or progressive lenses, which provide the patient with good vision at various distances. It is very important, however, that anyone who tries these lenses is aware of the difficulty of use that these lenses can cause.
All types of lenses for presbyopia must be checked often and possibly replaced to ensure optimal correction as visual impairment progresses.
A new frontier in the correction of presbyopia is represented by laser eye surgery and cataract surgery, in which multifocal or EDOF intraocular lenses (IOLs) are put in place of the natural crystalline lens. However, a thorough evaluation is required by an ophthalmologist to identify patients who can effectively benefit from this type of intraocular lens.
