eye health

Presbyopia

The accommodative capacity of the human eye is reduced over the years due to a progressive hardening of the central portion of the crystalline (nucleus). It loses water, hardens and increases its refractive index, becoming unable to change the shape of the lens itself for focusing.

This causes the curvature of the crystalline lens itself to increase, thus increasing its convergence capacity. All this translates clinically into a progressive removal of the so-called next point, that is the closest point that can be focused with the maximum power of accommodation. The next point, at 10 years old, is about 7-8 centimeters from the eye, at 45 at 25 centimeters and at 60 years is about 1 meter.

Symptoms

To learn more: Symptoms Presbyopia

The patient with presbyopia becomes aware of his condition because he is no longer able to focus objects on the normal distance, but must remove them. The classic example is the removal of the newspaper at the time of reading.

Age of Onset

Presbyopia occurs in emmetropia around the age of about 45, in hypermetropia a little earlier and in myopia later. Indeed, the short-sighted will have the feeling that their refractive defect is better. In astigmatism, depending on whether it is miotic or hypermetropic, it will manifest itself earlier or later.

Presbyopia, therefore, is not a pathology but a paraphysiological (normal) phenomenon linked to aging.

Very important to keep in mind is the fact that any apparent improvement in presbyopia after the age of 65 must always suggest a myopization due to a change in the refractive index of the crystalline lens that occurs in the cataract (a disease characterized by the progressive opacification of the lens, which under normal conditions is transparent).

Correction of presbyopia

It is necessary around the age of 45 and is implemented through the use of bifocal lenses that converge in near vision.

The use of contact lenses and surgical laser treatment is also possible.

EyeMyopiafarsightednessPresbyopiaAstigmatismGlaucoma