Far-sightedness is optic vision impairment when the visual clarity of objects which are close (20–30 cm from the eyes) is deteriorated. Far-sightedness is often accompanied by complaints of rapid fatigability of the eyes and headaches. A person with high degrees of far-sightedness has blurred vision for both far and close distances.
The eye performs the function of a high precision "camera with multifocal lenses". When we look at an object, the rays of natural or artificial light are reflected on its surface, they pass the anterior part of the eye and are reflected by the system of eye lenses, then they get inside the eyebulb through the pupil and are focused in one point on the posterior pole of the eye, covered by the nervous tunic - the retina. Due to precise focusing a person gets a clear image.
In far-sightedness the form of the eyebulb is narrowed. The lightwaves, entering the eye, are focused in the imaginary point behind the posterior pole, not getting on the retina, which results in the blurred image.
There are also periods of physiological far-sightedness during the life:
- At the age of one to four years. At the age of about four the sizes of the eye become balanced, hyperopia disappears and normal vision is achieved.
- Age-related far-sightedness (presbyopia). Age-related far-sightedness is not a disease; it is a physiological change of the human natural lens. It is condensed with time and stops performing the function of the focusing lens, which conditions the necessity of plus eyeglasses for fine details at close distances.
Far-sightedness above the age-related norm in childhood requires obligatory correction with eyeglasses, because the absence of treatment may lead to the development of heterotropia and ambliopia ("lazy eye").
At the age of 20–40 a person may not notice an insignificant degree of far-sightedness. Due to good work of muscular-ligamentous apparatus and adaptive reactions these visual impairments do not cause any complaints. This group of patients has earlier age-related presbyopia.
Degrees of far-sightedness:
- low degree – hyperopia to +2.0 diopters;
- medium degree – hyperopia to +4.0 diopters;
- high degree – hyperopia above +4.0 diopters;
- correction with eyeglasses;
- correction with contact lenses (hard, soft, Paragon night lenses);
- refractive laser correction (LASEK, LASIK);
- implantation of a multifocal lens ReSTORE.
Correction with eyeglasses may be prescribed in the early childhood. Correction with contact eyelenses requires taking care of lenses, thus the child's readiness and maturity are taken into consideration.
Refractive surgery is laser correction of far-sightedness, performed at the age of 18, at the patient's request and with no contraindications.
In case of age-related presbyopia it is possible to substitute the natural lens with a multifocal artificial lens ReSTORE. This kind of correction is preferred for cloudy lenses.