Myopia, presbyopia, astigmatism, hyperopia are disorders that affect our vision and can affect our day to day life.
How to choose your spectacle lenses to limit their effects?
This is what we will explain to you in this blog because although these terms have entered our everyday language, their exact meaning and their solution is sometimes little known.
In the case of a myopic eye, the focal point is located in front of the retina. As a result, far vision is blurred.
To restore sharpness of vision, single vision glasses are used with divergent single vision lenses. They allow the image to be repositioned on the retina.
Presbyopia is a natural visual impairment associated with aging of the eye. Over time, the lens gradually loses its flexibility and is no longer able to bulge out enough to accommodate. Near vision becomes blurry.
This aging process, which actually begins at a young age, is usually felt between the ages of 40 and 45. From this moment until around the age of 60, presbyopia progresses rapidly, which requires regular eye control for an effective adaptation of the visual correction.
There are different visual solutions to correct the presbyopia: progressive lenses, proximity glasses, even single vision lenses.
The astigmatic eye does not focus all the light rays at same place on the retina. The image is formed in two distinct points, which causes an imprecise vision of near as of far.
This visual defect is generally due to an irregularity of the cornea, of which the curvature is slightly oval instead of to be round.
To correct this ametropia, we use single vision glasses with toric lenses, the curvature of which compensates for that of the retina.
Hyperopia: strong >
The hyperopic eye has difficulty seeing sharp up close because the focal point is behind the retina. He must constantly accommodate to move the focal point forward. The image becomes blurry when the eye reaches the limit of its accommodation capacities.
To correct this visual disturbance, converging, convex single vision lenses are used, which replace the image on the retina .