What is myopia?
The myopic eye is an eye that is too long or too convergent, which means that the image of an object is not clear, as it is formed in front of the retina. Without correction, myopia consists in poor long-distance vision and satisfactory near vision. The more severe the myopia, the worse a person’s long-distance vision and the more he has to draw objects near to him in order to see them clearly; this is particularly the case with very severe myopia patients who read well at a distance of 10 cm, but fail to recognize their neighbors at a distance of 3 meters. Myopia correction is carried out by means of ophthalmic lenses or concave contact lenses, through which the image is pushed towards the back of the retina to achieve clear vision.
The same effect can be brought about by flattening the center of the cornea using laser (overall diminution of the eye convergence).
Surgical treatment of myopia is primarily based on Lasik. Up to -10 diopters and whether or not associated with astigmatism, all forms of myopia can be treated using laser, expect in cases involving specific corneal contraindications (shape and thickness).
At more than -10 diopters, intraocular lenses are indicated: phakic refractive lens implantation (preserving accommodation by conservation of the eye’s natural crystalline lens) prior to 40 years of age; and crystalline exchange after 50 years of age (replacement by an artificial crystalline lens of the natural crystalline lens, which has lost its physiological accommodation capacities).