Contact lens set.

The supply of presbyopic contact lenses currently represents a not yet been satisfactorily solved problem. This is partly due to the large number of different parameters for the to be selected lens design, such as contact lens geometry, arrangement and size of the near / far area and the value for the Nahaddition that not enable reproducible and efficient production of such contact lenses. Another difficulty is the irrational adaptation and delivery of the lenses to presbyopic contact lens wearers. A conventional adjustment runs for example as follows:<ul><li>1. adapter stage: monofocal lens, particularly soft lens</li><li>2. matching stage: Anpaßlinse with centering or trial lens</li><li>3. adapter stage: adjusting an approximately matching bifocal lens</li><li>4. matching stage: determination and order the prescription lens</li><li>5. adapter stage: adjusting the prescription lens</li><li>6. matching stage: Verification of the seat and overrefraction</li><li>7. matching stage: determining the final bifocal lens; Completion of the final prescription lenses</li></ul>

Such fitting procedure usually takes six to eight weeks.

Known bifocal contact lenses are designed on the bivisuellen (simultaneous) principle or the alternating principle. For bifocal contact lenses after the simultaneous principle it is known cylindrically segmented, radially segmented or vertically segmented lenses (Reprint from the NOJ, June 1969 Günter Giefer "The various Bifokallinsensysteme - possibilities and limitations of their adaptation"; DE-PS 32 22 099) to use ,

While sharp images of near and distant objects in the simultaneous bifocal contact lenses on the retina of the contact lens wearer simultaneously Bifokalkontalktlinsen are constructed from alternating type so that the affected area and the remote zone of the contact lens is alternately are the eye pupil, and accordingly only a sharp image for the respective viewing zone on the retina is present. The disadvantage is considered by the alternating type in Kontaktlisen that image jumps occur when switching between distance and near.

Furthermore, bifocal contact lenses with sliding lensmeter transitions known, between a maximum and minimum vertex power force include all values. Even bifocal contact lenses with minimal spherical aberration are known. This is a relatively large depth of field are generated (DOZ KL 7/1988 pages 74, 75 and SO 9/1989, pages 34 to 37). Also zoom lenses for presbyopia known (Contactologia 11 D (1989), pp 122-125). The large number of known lens types shows that a satisfactory development of a Presbyopenkontaktlinse has not yet been found.

Object of the invention is in this context to provide a contact lens set, with the adaptation and delivery is greatly simplified to Presbyopenkontaktlinsenträger.

This object is achieved by a contact lens kit, which consists of a plurality of contact lenses whose vertex values ​​differ from one another in certain gradations and is characterized in that<ul><li>each lens of the sentence as a multifocal, especially bifocal lens, is formed and having a single standard diameter for the entire set of lenses and a uniform back surface geometry; and</li><li>between the distance portion and near portion of each lens a uniform for the entire lens set standard addition of vertex values ​​is provided.</li></ul>

Preferred back surface geometry elliptical geometry is put to use, as it is known for example from German Offenlegungsschrift 30 31 749th In the preferred uniform for the standardized lens set back surface geometry all cuts have with planes containing the optical axis of the lens, a uniform for the entire lens set radius of curvature within a range of 6.0 to 9.0 mm and a uniform for the entire contact lens set numerical eccentricity in the range of 0.2 to 0.9.

Preferably, the unitary value of standardized for the entire lens set Nahteiladdition in a range of + 2.0 to + 3.5 diopters is. A preferred range of Nahteiladdition is 3.0 to 3.5 diopters, with a value of 3.25 for the Nahteiladdition is preferred.

Preferably a multifocal, especially bifocal contact lens from the simultaneous type is used. for this purpose are known per se into question cylindrically segmented, radially segmented and vertically segmented lensmeter zones (z. B. German Patent 32 22 099) for the distance portion Nahund apply. Preferred is a coaxial arrangement of the lensmeter zones, in particular the Nahund distance portion, wherein the center which may have the near or far zone, has a diameter of about 3 mm. Preferably, the near portion is located in the center. This has the advantage that it to a surface expansion of the distance portion, which is then placed peripherally around the central reading portion, used for example in sudden blackout.

Preferably, any standardized bifocal contact lens in the contact lens set having a corneasklerales Design. The standard lens diameter of each lens can have a uniform value in a range of 8.5 mm to 17 mm. In this way, remains on the lens design still plenty of room for fins, for example in the form of crescent stabilizing surfaces, such as are known from the German Patent 32 22 099th The arrangement of the near and distant parts of the lenses described in this patent may come in the invention apply.

The gradation of the vertex values ​​of the individual lenses of the contact lens is 0.25 diopters and preferably set, but can also be chosen larger. It comes with such a gradation from a adaptable and sale set of 50 lenses, being vertex values ​​of plan up - considered 6.0 diopters. Preferably, the lenses are the lens set to the vertex values ​​of the distance correction order.

This standardized sale set the adjuster is able to cast the lens directly from the sale rate. It has a sales record, as is usual for the adjustment of short-sighted. The adjuster needs the selection of lenses make only after the required distance correction. In this way, the presbyopic contact lens wearers comes directly to an optimal correction, and he can convince himself immediately from the operation of the lens. With the described standardized multifocal, especially bifocal lens, a large percentage of all Presbyopic can be adapted. When using a contact lens is required in principle, an addition which is to +0.5 diopters above the vertex value of the appropriate pair of glasses.

Due to the standardized parameters of the lens is also a rational production of lenses, for example by the so-called full mold process, is possible. This applies to both hard and soft lens, with different oxygen permeabilities and different water contents can be adjusted by appropriate formulation of the contact lens materials.