GRADUALLY INCREASED FOCAL POWER AND CHANGE-PROFILED FOCAL POWER LENSES Russian patent published in 2005 - IPC

FIELD: ophthalmology.

SUBSTANCE: goal of the invention is to make lenses with gradually increased focal power. Distribution of focal power between zones of far and near vision should meet requirements related to peculiarities of path of men's glance who uses the lenses and value of refraction. Distribution of focal length is performed without introduction of undesired astigmatism. When making lenses for glasses the two steps are obligatory. The first one is to measure path of glance to a person using lenses and required power of refraction when the person in lenses watches remote object. The second step corresponds to making lens having channel focal power profile on the path of person' s path of glance and meeting the requirements applied to refraction power. Second step is performed by means of making a lens that has first surface, first channel and first channel focal power profile and second surface that has second channel and second channel focal power profile , where lens channel focal power profile has to be vector sum of profiles of channel focal power.

EFFECT: reduced astigmatism.

21 cl, 6 dwg