| 摘要 |
The invention relates to a method for producing parastigmatic surfaces and lenses, and to parastigmatic surfaces and lenses produced by this method, for use in the ophthalmological and optometrical fields, both in optical diagnostic and evaluation devices and instruments, and in optical vision correction elements. For that purpose, superficial refractive surfaces or sectors that specify smooth changes in curvature between main orthogonal or non-orthogonal meridians are specified, in an inharmonic form, according to an analytical expression with polar co-ordinates involving a recursive variable that is a function of ophthalmic parameters, such as the apical curvatures in the main meridians, the conic constants of the main meridional curves, the positioning angle of the first main meridian, parastigmatism and the eccentricity thereof. These thus described parastigmatic surfaces are produced, in combination with other conventional surfaces, such as spherical, cylindrical, toric, aspherical surfaces, etc... by means of production techniques such as machining, moulding, ablation, printing, shaping and others. |
