A concave lens is a diverging lens

Concave lens

Concave lenses, also known as diverging lenses or concave lenses, are thicker at the edge than in the center. So they get wider towards the edge and are curved inwards. Concave lenses are used to correct myopia (myopia) used and in the Optics also known as minus glass, because in myopia the Glass thickness is provided with a minus. On the contrary, serve Convex lenses the correction of a Hyperopia (Farsightedness).

In the case of myopia, the Refractive index can be corrected by a concave lens (diverging lens) so that the light rays meet again on the retina. This is achieved by refracting the light rays through the special concave lens shape in such a way that they are scattered again on the exit side. Concave lenses extend the path of light in the eyeball, which is too long in myopia, and ensure that the focal point of the light rays is exactly on the retina again. With perfectly adapted glasses, the light is focused exactly in the Yellow spot (Point of sharpest vision, also called fovea centralis).

 


 

Concave lenses
Concave lenses, also called divergent lenses, are thicker at the edges than in the middle. So, they broaden towards the edges and are curved inward. Concave lenses are used with correcting myopia (near sightedness) and are in optics also called minus glasses, because of the minus in front of the diopters strength in case of myopia. Contrary hereto, convex lenses are used for correcting hyperopia (farsightedness).

In order to enable a person with myopia to a clear far distance vision again, the refraction value must be corrected by a concave (divergent) lens in a way, that the light rays can focus again on the retina. This can be achieved by refracting the light rays by means of the special concave lens, so that they are diverged again behind the retina. Thus the concave lenses are elongating the way of the light in the eyeball, which is too long with near sightedness, and assure that the focus of the light rays is exactly on the retina, again. With perfectly adjusted glasses focus of light happens exactly in the yellow spot (point of clearest vision, also called fovea centralis).