Farsightedness or hypermetropia – this is a pathology of refraction of the eye, in which the image of objects is not formed on the retina, and behind her. In other words, the peculiarity of the refraction of the eye apparatus in farsightedness is that, what rays, coming from objects, intersect behind the retina, therefore far-sighted people see better distant objects, than relatives. Therefore, in order to obtain a clear image on the retina, it is necessary to increase the refraction with special biconvex lenses.
Causes of farsightedness
The cause of farsightedness is more often congenital due to a significantly shortened eye axis – Less 23,5 mm – so called “short eyes”, or weakened refractive power of the cornea.
Diagnosis of farsightedness
Most often people, who have farsightedness, do not complain about their eyesight. With a weak degree of farsightedness (2 diopters) far and near vision is quite good, but there may be complaints of quick fatigue, headache with significant visual stress.
The first symptoms appear in childhood. Children do not study well, get tired quickly, cannot concentrate on doing work, are cranky, sleep badly. Early diagnosis and appointment of optical correction (glasses, contact lenses) allows to reduce the risk of such complications, such as strabismus and amblyopia.
With an average degree of farsightedness (from 2 to 5 diopter) – distance vision remains good, and close – already a little worse.
With a high degree of farsightedness (above 5 diopter) – vision is poor and in the distance, and approx, since all the possibilities of the eyes to focus the image on the retina have been exhausted. This applies even to those subjects, which are far away.
Farsightedness correction
Farsightedness correction can be ocular, contact lenses or surgery.
Glasses – the most common method of farsightedness correction. But they do not provide 100% vision corrections and significantly limit side vision, disrupt the stereoscopic effect and spatial perception, which is especially important for drivers.
Contact lenses are used to correct farsightedness, which is often accompanied by amblyopia (low vision). In these cases, the use of contact lenses becomes therapeutic, because only the creation of a clear image on the fundus is the most important stimulus for the development of vision.
There are several types of operations to eliminate farsightedness:
Hyperopic Lasik – a flap is formed from the surface layers of the cornea, it is discarded and the periphery of the central optical zone is vaporized with an excimer laser in the form of a ring, causing the cornea to become more convex and, as a consequence, its refractive power increases, which allows you to get the effect of the operation.
Hypermetropic Artifakia – the essence of the operation consists in removing the own lens and installing an artificial one, which has a higher optical power.
