Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02C—SPECTACLES; SUNGLASSES OR GOGGLES INSOFAR AS THEY HAVE THE SAME FEATURES AS SPECTACLES; CONTACT LENSES
  • G02C7/00—Optical parts
  • G02C7/02—Lenses; Lens systems ; Methods of designing lenses
  • G02C7/04—Contact lenses for the eyes
  • G02C7/049—Contact lenses having special fitting or structural features achieved by special materials or material structures
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C39/00—Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor
  • B29C39/02—Shaping by casting, i.e. introducing the moulding material into a mould or between confining surfaces without significant moulding pressure; Apparatus therefor for making articles of definite length, i.e. discrete articles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
  • B29D11/00—Producing optical elements, e.g. lenses or prisms
  • B29D11/00009—Production of simple or compound lenses
  • B29D11/00038—Production of contact lenses
  • B29D11/00125—Auxiliary operations, e.g. removing oxygen from the mould, conveying moulds from a storage to the production line in an inert atmosphere
  • B29D11/00192—Demoulding, e.g. separating lenses from mould halves
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B1/00—Optical elements characterised by the material of which they are made; Optical coatings for optical elements
  • G02B1/04—Optical elements characterised by the material of which they are made; Optical coatings for optical elements made of organic materials, e.g. plastics
  • G02B1/041—Lenses
  • G02B1/043—Contact lenses

Definitions

• the present application relates to a "soft" contact lens with excellent wear properties.
• a contact lens made of silicone in which a radial cross section on the inner surface has an edge region between an inflection point and the outer edge, in which the cross-sectional contour is convex, in particular with a radius between 0.1 and 10 mm. Due to this edge contour, the lens slides particularly easily on the tear fluid film.
• the problem is solved by a method in which a silicone precursor material is introduced and polymerized between a female and a male mold, and the polymerized contact lens is released from the mold by means of a contact lens-swelling liquid and finished without edge trimming.
• a contact lens-swelling liquid and finished without edge trimming This avoids the occurrence of a cut edge that might be distracting.
• FIG. 4 shows a flowchart for a production method of the contact lens according to the invention
• FIG. 5 shows a cross-sectional view of one for the production according to FIG
• Figure 4 shows a suitable molding apparatus.
• FIGS. 1 and 2 The general form of a contact lens is shown in FIGS. 1 and 2: the inner surface 1, which faces the cornea and floats in use on a tear fluid film, is concave in the central region Z, namely rotationally symmetric-aspheric with a cone constant of approximately -0.1 to -0.5, so slightly elliptical pointed. In principle, however, this surface can also deviate from rotational symmetry if physiological conditions so require.
• the outer surface 2 of the lens is of course convex with an amount slightly different from that of the inner surface to provide the desired dioptric power.
• the curvatures or radii deviate from the central values in the following way: On the outer surface, an annular region 4 with a stronger (inward) curvature, that is to say a smaller radius, joins radially to the central region. On the outside, this can be followed by an area 5, which is again curved more slenderly, even conically (that is, unconstrained), or slightly outwardly (ie, negative). In terms of magnitude, however, the curvature here is always smaller (that is to say the radius is greater) than in the first-mentioned transitional region 4, d. H. the lens runs smoothly.
• the inner surface 1 has radially to the central region with the elliptical surface then also an annular area, but less curved, that is flatter, which corresponds to a larger radius of curvature in this area.
• the radius of curvature in a sectional plane containing the optical axis of the lens is meant the radius of curvature in a sectional plane containing the optical axis of the lens.
• the line formed by the inner surface and the cutting plane passes through a turning point 6, ie the curvature of the line is first zero and then positive. For the Gau 1 see surface curvature, this means a change to negative values.
• the area 7 then adjoins this area, where the inner surface of the contact lens conforms to the global tangential plane;
• the curvature in the main plane of curvature perpendicular to the radial cutting plane is zero, so that the Gaussian surface curvature becomes zero and changes even more positively in the immediate edge region.
• the present invention gently on a cut edge-free outer edge to ongoing annular areas (see Figure 2) that a trouble-free sliding of the contact lens on the tear fluid film and at the same time a trouble-free sliding of the eyelid is made possible on the contact lens.
• the radius of the inner surface, ie the inverse curvature, along the radial cut surface for example between 0.1 and 4 mm, or on the one hand about 0.5 mm and / and on the other hand, less than 2 mm.
• the radial extent of the negatively curved area can be 1 ⁇ m to 1 mm, for example, on the one hand above 10 ⁇ m and / or on the other hand below 100 ⁇ m.
• FIG. 4 shows a flow chart of a method according to the invention.
• a female and a male mold are provided, and a precursor material for poly (dimethylsiloxane) is introduced into the female mold, sealed with the male part and kept at a temperature between 15 ° C-160 ° C for a period of 12-720 minutes polymerizes Sl (molding).
• the two moldings are rotated against each other by 180 ° or another sufficiently large angle (> 20 °), as long as the reaction mixture is just still viscous (over 1000 cP, typically about 4000 cP), so that excess silicone reliably separated and is displaced into the annulus between the moldings.
• the surface tension described above is also produced by the influence of the surface tension, which makes it possible to dispense with edge trimming or other edge processing which produces a cut edge (eg stamping).
• edge trimming or other edge processing which produces a cut edge (eg stamping).
• the dipole moment of the solvent should be no more than 0.2 Debye.
• the starting material can be a liquid 2-component silicone from NuSil with a DK value of over 700 barrers. If desired, the lens is steam sterilized after evaporation of the solvent in vacuo at above 120 ° C.
• FIG. 5 a two-part molding mold is shown, which is suitable for carrying out the method described above.
• the lower female part 10 first takes up the reaction mixture and is then closed with the upper, male part 12, leaving a filled with the reaction mixture space 11 between them.
• the lower part 10 has shaped bevels 13 ', 13 ", which facilitate the assembly and the separation of the mold parts 10 and 12 from each other. space is designated 14.
• the inventively formed contact lens can be used as a dressing lens, i. with or without refractive power to physically protect the cornea from irritation. This may be useful as a flanking, inherently non-therapeutic measure in a medical therapeutic eye treatment.
• a "predominant existence” means a mass fraction of more than 50%, in particular of more than 90% in its entirety.
• curvature is to be understood in each case as the inverse radius of curvature, ie the radius of the osculating circle, the sign being positive for convex surfaces and negative for concave surfaces.
• the Gaussian surface curvature is the product of the two main ⁇ curvatures, so then negative when the two principal curvatures have different signs (saddle face), and zero when one or both principal curvatures are zero (z. B. cylinder and cone surface) ,

Landscapes

• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• Ophthalmology & Optometry (AREA)
• Health & Medical Sciences (AREA)
• Optics & Photonics (AREA)
• General Physics & Mathematics (AREA)
• Manufacturing & Machinery (AREA)
• Mechanical Engineering (AREA)
• General Health & Medical Sciences (AREA)
• Eyeglasses (AREA)
• Moulds For Moulding Plastics Or The Like (AREA)
• Casting Or Compression Moulding Of Plastics Or The Like (AREA)
• Molding Of Porous Articles (AREA)

Priority Applications (13)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (14)

Cited By (2)

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Citations (5)

Family Cites Families (23)

• 2012
  • 2012-02-01 EP EP12000660.6A patent/EP2597492B1/de not_active Not-in-force
  • 2012-02-01 ES ES12000660.6T patent/ES2474122T3/es active Active
  • 2012-02-01 PL PL12000660T patent/PL2597492T3/pl unknown
• 2013
  • 2013-02-01 JP JP2014522122A patent/JP2014526063A/ja active Pending
  • 2013-02-01 AU AU2013206389A patent/AU2013206389B2/en not_active Expired - Fee Related
  • 2013-02-01 RU RU2014135281A patent/RU2014135281A/ru not_active Application Discontinuation
  • 2013-02-01 US US14/351,509 patent/US8974054B2/en not_active Expired - Fee Related
  • 2013-02-01 BR BR112014010575A patent/BR112014010575A2/pt not_active IP Right Cessation
  • 2013-02-01 DK DK13702346.1T patent/DK2656118T3/da active
  • 2013-02-01 WO PCT/EP2013/000326 patent/WO2013083856A1/de not_active Ceased
  • 2013-02-01 PL PL13702346T patent/PL2656118T3/pl unknown
  • 2013-02-01 CN CN201380018607.6A patent/CN104395781B/zh not_active Expired - Fee Related
  • 2013-02-01 EP EP13702346.1A patent/EP2656118B1/de not_active Not-in-force
  • 2013-02-01 EP EP13005873.8A patent/EP2711740A1/de not_active Withdrawn
  • 2013-02-01 PT PT137023461T patent/PT2656118E/pt unknown
  • 2013-02-01 ES ES13702346.1T patent/ES2451090T3/es active Active
  • 2013-02-01 SI SI201330002T patent/SI2656118T1/sl unknown
• 2014
  • 2014-01-28 AR ARP140100254A patent/AR094602A1/es unknown
  • 2014-12-17 JP JP2014255451A patent/JP2015111267A/ja active Pending

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