Lensmeter

The Lensmeter (synonym: Lens meter ) is a device that is used in ophthalmology and optometry to determine the vertex power. Thus, the refractive index of optical visual aids (spectacles ) is then determined. From a positive vertex power is always present when parallel rays of light falling on the lens of the visual aid to be broken each other. The meter ultimately measures the "strength" of the visual aid and are the spherical and cylindrical values ​​in diopters.

There is significantly lenses with the eye-side vertex power, the eye-side surface has to be measured on the Lensmeter.