Contact lenses for myopia

Correct nearsightedness with contact lenses

Background : What is a visual defect?

When the eye is perfect, the visual image of nearby objects is formed on the retina. The lens bulges according to the distances in order to restore a sharp image: it is the accommodation. It operates from ten centimeters to infinity. When the image of objects is not formed on the retina, vision is blurred. This is called a refractive error or ametropia : it includes all vision defects: astigmatism, hyperopia, myopia and the presbyopia (after 40 when the vision becomes more difficult).

Myopia is characterized by blurred vision from afar. Driving, watching a movie, playing certain sports become uncomfortable.

A good close vision but a bad one from a bigger distance is the result of eyes being "too long". The perceived image is not formed on the retina, but in front of it. The higher the myopia, the shorter the viewing distance. The shortsighted person has to wrinkle to try to restore a clear vision from a distance.

Contact lenses for myopia :

The argument for contact lenses is a better aesthetics as the myopic glasses could be very thick in high myopia. However, wearing contact lenses not only allows short-sighted to have a better correction in case of high myopia, but also to have a better visual field above the eye (which is limited by the edges of the glasses frames). The use of contact lenses becomes important for sporting or professional activities by removing some of the improper arrangement of wearing glasses. However, the contact lens on the cornea is not without risks and sometimes prone to allergic reactions of the eye.

The solution : a divergent contact lens or concave so the edge are thicker than the center, corrects nearsightedness by pushing the image on the retina, thus giving a good view to infinity.

Contact lenses for myopia, the lenses are called "spherical" (as for the correction of hyperopia).