The word presbyopia (lat. presbyopia) in Greek “presbus” means an old person. Presbyopia is a condition associated with age and a decline in the maximum accommodation power of the eye due to changes in the refractive system of the eye.
As the eye lens in presbyopia loses its elasticity and becomes stiffer, it also loses its ability to accommodate. The point of clearest near vision (Punctum proximum) gradually moves further away from the eye. A person cannot focus near rays on the retina, i.e. he has difficulties with near vision.
Presbyopia does not affect the far point (Puntum remotum), it remains in the state it was in before the onset of presbyopia.
A farsighted person without correction constantly accommodates and does not have sufficient accommodation strength to focus near rays. For this reason, presbyopia will be noticed sooner. A farsighted person will need error correction in order to be able to focus the near rays normally.
In a myopic person, the point of the clearest near vision is closer than usual. A short-sighted person without distance correction can focus near rays without accommodation. Thus, a short-sighted person does not even have to notice that he has lost the power of accommodation, because in most cases he will be able to focus the near rays. A myopic person, depending on the degree of myopia, will not always need nearsightedness correction. When working at close range, she will notice that proper distance correction bothers her and will not use it to see at close range (she will take off her distance glasses, and with contact lenses for distance she will not be able to read at close range).
Signs of senile farsightedness:
- arms become “too short”
- the patient has difficulties when working at close range
- stronger lighting is needed for close work
- eye fatigue
- headache
- asthenopia (fatigue, burning, etc.)
Correction of short-sightedness – presbyopia
Elderly farsightedness is corrected by positive addition, addition (ADD) to distance correction. When prescribing nearsightedness correction, it is necessary to pay attention to the type of work a person does and set the nearpoint to the required distance. In most cases, the working distance and close distance are not the same. As the eye lens becomes less elastic with age, the accommodative amplitude becomes weaker, and the diopter used to correct vision becomes greater.
Nowadays, we correct senile farsightedness in several ways:
- glasses for near work, which the patient must take off when looking at distance
- bifocal glasses
- progressive (multifocal) glasses
- progressive contact lenses
- operative-refractive surgery
Autor:
bc. Livio Svržnjak, optometrist
