Shortsightedness - Myopia
Myopia is the most popular ametropia worldwide. Babies are farsighted mostly. Due to growth this farsightedness is getting reduced and often a shortsightedness is developed during the schooldays. This process often is not stopped till the age of 25. The persons concerned cannot see people or things in a far distance properly. Even with a low myopia of about -1,00 dpt the vision gets blurred at a distance of 1 meter. Myopic students often squint their eyes to look at the blackboard. As a myope either the refraction power of your eye at relaxed vision is too much or your eyeball is grown too long. In both cases the light rays, which enter the eye, don’t match directly at the retina, but in front of it. That’s why the perceived picture on the retina gets blurred. Besides the normal physiological myopia a shortsightedness can also be developed due to diabetes or as a side effect of pharmaceuticals.
Correction of myopia
The eye has no possibility to compensate the shortsightedness on its own. Even a myopia of -0,5 dpt reduces the vision for far distance of 50%, so a myopia has to be corrected. Just some years ago there were only few possibilities in Germany to correct myopia: glasses or contact-lenses.
The most popular correction are glasses. With glasses myopes can see their surrounding exactly again. But the visual field is defined by the size of the glasses. Another disadvantage is the distance to the eyes, which makes you see the surrounding smaller. Even at doing sports glasses can be cumbersome. These limitations rise with increasing myopia.
Contact-lenses can also correct myopia. And they compensate nearly all disadvantages of glasses. The visual field is unlimited and the visual acuity is often even better. In addition contact-lenses are more comfortable than glasses doing sports. With high myopia the amenities you have with contacts exceed the ones you have with glasses.
In contrast the correction with Laser surgery is relatively new. Due to the Laser-technique thin layers of the cornea are ablated in the center. Thereby the cornea gets thinner and flatter in the center. The higher the myopia, the more has to be ablated. The different procedures (PRK, Lasik, Lasek) were improved during the last years to reduce the risk for the patient. The lowest risk is till 6 diopters of myopia.
Orthokeratology to Myopia-Control
Already since 40 years special rigid gas permeable contact-lenses are fitted in the USA in order to correct the myopia permanent and to control the growth. The safety of this procedure (orthokeratology) was increased with the rising oxygen-durability of the contact-lens materials. Today these contact-lenses are produced of materials with the maximum oxygen-durability.
The new developed and current contact-lens designs from Europe offer a considerable higher efficiency. Also studies from the USA and Asia are very auspicious relating to the repressive impact on the growth of myopia due to this procedure.