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
  • G02C7/041—Contact lenses for the eyes bifocal; multifocal
  • G02C7/044—Annular configuration, e.g. pupil tuned

Definitions

• the present invention relates to multifocal contact lenses and methods of using and making the contact lenses.
• Presbyopia is a condition in which a person loses the ability over time or has a decreased ability to focus clearly on nearby objects. It is believed that presbyopia may be caused, at least in part, by a decreased accommodation of the lens in the patient's eye. Presbyopia is most frequently diagnosed in people who are about forty years old or older. An emerging presbyope can be understood to be a person who is beginning to show symptoms of presbyopia, for example, a person who exhibits good accommodation but who can't clearly focus on near objects.
• Contact lenses have been described as being useful in correcting presbyopia.
• a presbyopic person wears one contact lens for distance vision in one eye, and a second contact lens for near vision in the other eye.
• Multifocal contact lenses have also been described as being useful for correcting presbyopia.
• Some multifocal lens systems consist of two multifocal contact lenses with each lens including alternating concentric rings of different powers.
• the first contact lens has a central distance vision zone and the second contact lens has a central near vision zone. The central zones are surrounded by one or more rings having different optic powers.
• both contact lenses have central distance vision zones and have multiple rings of different optic powers surrounding the central distance vision zone, and the number of rings surrounding the central distance vision zone differ between the two lenses depending on whether the lens is for the dominant eye or non-dominant eye.
• Multifocal contact lenses methods of improving or correcting vision, and methods for producing the multifocal contact lenses are described.
• the present pairs of multifocal contact lenses are useful in correcting or improving vision of patients who require a power correction of +1.25 diopters or less.
• the present contact lenses are useful in correcting vision of an emerging presbyopic patient, which can be understood to be a person who is beginning to show symptoms of presbyopia and who requires no greater than about + 1.25 diopters of add power.
• pairs of multifocal contact lenses are provided.
• the present pairs of multifocal contact lenses consist of two multifocal contact lenses. Each lens of the pair has an optic axis.
• each contact lens of the pair includes a central area that includes the optic axis.
• the central area provides substantially all of the distance optical power of the multifocal contact lens.
• Each contact lens of the pair also includes an annular area surrounding the central area. The annular area extends radially outwardly from the central area toward a lens edge. The annular area provides intermediate optical power and near optical power.
• a multifocal contact lens system includes the pair of multifocal contact lenses.
• the present methods include a step of providing the present pairs of multifocal contact lenses described herein.
• the providing can be performed by a contact lens manufacturer to a distributor or lens wearer, a contact lens distributor to a doctor or a lens wearer, or by a doctor to a lens wearer.
• methods of producing contact lenses include a step of forming the present pairs of multifocal contact lenses described herein.
• FIGS. IA and IB illustrate plan views of a pair of contact lenses as described herein.
• Multifocal contact lenses, methods of improving or correcting vision, and methods for producing the multifocal contact lenses are described. Although the present lenses and methods will be focused on the use of the lenses in correcting vision of an emerging presbyopic patient, the present lenses and methods can be useful in correcting vision of other patients who require a power correction of +1.25 diopters or less.
• a person is typically diagnosed with presbyopia by a skilled professional using conventional eye examination techniques that, among other things, are used to evaluate accommodation of the person's eyes. However, some early signs of presbyopia may be apparent to the patient without the eye exams, such as the decreasing ability to focus on near objects while still being able to focus on distant objects.
• An emerging presbyope is a person who is beginning to show symptoms of presbyopia and who requires no greater than about + 1.25 diopters of add power.
• Previously methods of correcting presbyopia in presbyopic patients such as correcting vision of patients that require greater than +1.25 diopters of add power, that utilize two contact lenses of different designs, it has now been discovered that presbyopic people who require about +1.25 diopters of add power or less exhibit improvement in their vision using two multifocal contact lenses of substantially similar, and preferably identical, design.
• One benefit of using two contact lenses of substantially similar design is that the patient does not need to be concerned whether the correct lens is placed on the dominant eye (i.e., the eye that is predominant for distance vision) or the other non-dominant or dominated eye.
• an eye care practitioner is now able to provide vision correction to a patient, such as an emerging presbyope, independent of determining eye dominance.
• pairs of multifocal contact lenses are provided.
• the pair of multifocal contact lenses consists of a first contact lens and a second contact lens.
• Each contact lens of the lens pair has an optic axis that is typically at the center of the lens.
• Each contact lens has an anterior surface or front surface and an opposing posterior surface or back surface that is placed in contact with a person's eye.
• a peripheral edge surface defines the perimeter of each contact lens.
• Each multifocal contact lens of the lens pair comprises a central area that includes the optic axis of the contact lens.
• the central area provides substantially all of the distance optical power of the multifocal contact lens.
• Distance optical power refers to the amount of refractive power required to correct a lens wearer's distance vision acuity by a desired amount.
• Each multifocal contact lens of the lens pair also comprises an annular area surrounding the central area.
• the annular area extends radially outwardly from the central area toward a lens edge of the multifocal contact lens.
• the annular area has an outer border that is located radially outward from the central area and that is located radially inward from the lens edge.
• the annular area may be surrounded by a non-optic zone. However, in other embodiments, the annular area may extend to the lens edge.
• the annular area provides both intermediate optical power and near optical power.
• Near optical power refers to the amount of refractive power required to correct the lens wearer's near vision acuity by a desired amount.
• Intermediate optical power refers to the power between that of the near optical power and distance optical power. For example, intermediate optical power can be the power required to clearly view objects located at a distance from about 46 centimeters to about 80 centimeters from the eye.
• a pair of multifocal contact lenses 10 consists of a first contact lens 12a and a second contact lens 12b.
• Each multifocal contact lens 12a and 12b includes a central area 14 that includes the optic axis 20 of the contact lens.
• the central area 14 of each contact lens 12a and 12b provides substantially all of the distance optical power of the multifocal contact lens.
• Each contact lens 12a and 12b also includes an annular area 16 surrounding the central area 14. The annular area 16 extends radially outwardly from the central area 14 toward the lens edge 18.
• each contact lens 12a and 12b provides intermediate optical power and near optical power.
• a non- optic zone e.g., an area that is not used to correct a person's vision
• the annular area 16 can be represented as having an inner border proximate an outer border of the central area, and having an outer border spaced radially outward therefrom.
• the central area of each contact lens has a spherical surface
• the annular area of each lens has an aspherical surface.
• the spherical surface of the central area can provide a single dioptric power
• the aspherical surface can provide a transition of optical powers to provide a gradual correction of intermediate and near vision.
• the transition provided by the aspherical surface can be achieved by gradually decreasing the radii in the annular area from a region adjacent the perimeter of the central area to the outer edge of the annular area.
• the annular area is a progressive aspheric region of the lens.
• the illustrated embodiment of the present contact lens pairs includes only one annular area on each contact lens, other embodiments of the lens pairs may consist of two contact lenses, wherein each contact lens comprises a second annular area circumscribing the first annular area, the second annular area providing only a near optical power.
• the second annular area can be defined by a spherical surface.
• the present pairs of multifocal contact lenses are effective in correcting presbyopia or improving vision of an emerging presbyope. That is, the present pairs of contact lenses improve the vision of a person who requires an add power of + 1.25 diopters or less.
• each contact lens of the lens pair includes a central area that includes an add power no greater than +1.25 diopters.
• the central area of each lens includes an add power from about +0.25 diopters to about +1.25 diopters.
• each of the present contact lenses is made overrefractive relative to a person's prescription.
• the present lenses may have a refractive power that is 0.25 diopters greater than a power prescribed for the patient. This additional refractive power can help improve the vision of the patient for distant objects, near objects, or both.
• each of the multifocal contact lenses of the present lens pairs may provide a sphere power from about +4.00 diopters to about -6.00 diopters.
• each lens may have a single sphere power between +4.00 diopters and -6.00 diopters.
• the sphere power will be a value from +4.00 diopters to -6.00 diopters in 0.25 diopter increments.
• the annular area of each lens of the lens pair has a diameter of about 8.5 mm.
• the linear distance between the outer border of the annular area on opposite sides of the optic axis of the lens is about 8.5 mm.
• the central area of each lens of the lens pair can have a diameter from about 1.7 mm to about 3.0 mm. It can be appreciated that due to the smooth transition from the central area to the annular area, as described herein, a specific delineation of the central area diameter may not be particularly evident. However, in more specific embodiments, the central area may have a diameter of about 2.3 mm.
• the vision correcting areas can be provided on either the anterior surface of the lens, the posterior surface of the lens, or combinations thereof.
• the central area and annular area are provided on the anterior surface of the lens, hi that manner, the posterior surface can be configured to have a single base curve, or can otherwise be shaped to fit comfortably on a patient's eye.
• the present contact lenses of the contact lens pair can be lathed contact lenses, spincast contact lenses, or cast molded contact lenses. It can be appreciated that these types of contact lenses can have different physical features resulting from their method of manufacture, hi certain embodiments, including the illustrated embodiment, each of the contact lenses of the lens pair is a cast molded contact lens, hi other words, it is a contact lens obtained from a contact lens mold assembly formed from two contact lens mold sections in contact with each other to form a contact lens shaped cavity.
• the present contact lenses can be daily wear lenses or extended wear lenses, hi certain embodiments, each contact lens of the lens pair is a daily disposable contact lens (i.e., a contact lens that is worn on a person's eye only once and then discarded), hi comparison, as understood by persons of ordinary skill in the art, a daily wear lens is a lens that is worn on a person's eye, and is then cleaned and is worn on the person's eye for at least one additional time. It can be appreciated that daily disposable contact lenses are physically different, chemically different, or both compared to daily wear and extended wear contact lenses.
• each lens of the contact lens pair is a hydrogel contact lens, as understood by persons of ordinary skill in the art.
• each lens of the contact lens pair is a silicone hydrogel contact lens.
• Many hydrogel contact lenses are based on polymerizable lens formulations that include hydroxyethyl methacrylate (HEMA) monomers.
• hydrogel contact lenses are based on polymerizable lens formulations that include siloxane monomers, oligomers, or macromers.
• hydrogel contact lens materials include materials having the following US Adopted Names (USANs): etafilcon A, nelfilcon A, ocufilcon A, ocufilcon B, ocuf ⁇ lcon C, ocufilcon D, and omafilcon A.
• US Adopted Names USANs
• etafilcon A nelfilcon A
• ocufilcon A ocufilcon B
• ocuf ⁇ lcon C ocufilcon D
• omafilcon A omafilcon A.
• some embodiments of the present contact lenses may be hydrogel contact lenses that are based on lens formulations that contain 2,3-dihydroxypropyl methacrylate (GMA) alone or in combination with HEMA.
• GMA 2,3-dihydroxypropyl methacrylate
• silicone hydrogel contact lens materials include materials having the following USANs: acquafilcon A, balafilcon A, comfilcon A, enfilcon A, galyfilcon A, lenefilcon A, lotrafilcon A, lotrafilcon B, and senof ⁇ lcon A.
• each contact lens of the lens pair comprises the reaction product of a polymerizable composition comprising hydroxyethyl methacrylate (HEMA), 2- methacryloyloxyethyl phosphorylcholine, a crosslinker, and an initiator. Further embodiments may include an ultraviolet blocking agent, a tinting agent, or both.
• HEMA hydroxyethyl methacrylate
• 2- methacryloyloxyethyl phosphorylcholine a crosslinker
• an initiator may include an ultraviolet blocking agent, a tinting agent, or both.
• an embodiment of the present contact lens pairs consists of two multifocal contact lenses. Each multifocal contact lens is a cast molded contact lens.
• Each contact lens includes a vision correction portion that consists of a central area having a spherical surface and providing distance vision correction, and one annular area surrounding the central area, the one annular area having an aspherical surface and providing intermediate and near vision, where the near vision is provided by the more radially outward portion of the annular area.
• a further embodiment of the present contact lens pairs consists of two multifocal contact lenses.
• Each multifocal contact lens is a cast molded contact lens that is the reaction product of an omafilcon A lens formulation containing an ethyleneglycol dimethacrylate (EGDMA) crosslinker, an 2,2'-azobisisobutyronitrile (AIBN) initiator, and Reactive Blue 4 tinting agent.
• Each contact lens includes a vision correction portion that consists of a central area having a spherical surface and providing distance vision correction, and one annular area surrounding the central area, the one annular area having an aspherical surface and providing intermediate and near vision, where the near vision is provided by the more radially outward portion of the annular area.
• the diameter of the annular area is 8.5 mm and the lens diameter is 14.4 mm and the lens has a base curve of 8.7 mm.
• the lenses are provided with any sphere power from +4.00 diopters to -6.00 diopters in 0.25 diopter increments. These lenses have a water content of about 60%. These lenses are daily wear lenses that are disposed of every two weeks.
• a further embodiment of the present contact lens pairs consists of two multifocal contact lenses.
• Each multifocal contact lens is a cast molded contact lens that is the reaction product of an omafilcon A lens formulation containing an ethyleneglycol dimethacrylate (EGDMA) crosslinker, a bis(4-tertiarybutylcyclohexyl)-peroxydicarbonate (Perkadox) initiator , and Vat Blue 6 tinting agent.
• EGDMA ethyleneglycol dimethacrylate
• Perkadox bis(4-tertiarybutylcyclohexyl)-peroxydicarbonate
• Each contact lens includes a vision correction portion that consists of a central area having a spherical surface and providing distance vision correction, and one annular area surrounding the central area, the one annular area having an aspherical surface and providing intermediate and near vision, where the near vision is provided by the more radially outward portion of the annular area.
• These lenses are daily disposable contact lenses that are disposed of after a single use, that is after being worn for a time period less than 24 hours, such as from about 6 hours to about 16 hours.
• the present lenses can also include tone surfaces, rotational stabilization structures, or combinations thereof on one or both of the lenses of the lens pairs, especially when the patient has an astigmatism in one or both eyes.
• rotational stabilization structures that can be provided on the present lenses include ballasts, prism ballasts, thickened zones, thinned zones, protuberances on a lens surface, or combinations thereof. [0031] hi another aspect, methods of correcting vision of a person requiring vision correction of +1.25 diopters or less are provided.
• the present contact lens pairs are useful in correcting vision of an emerging presbyope, as described herein.
• the methods include a step of providing a pair of multifocal contact lenses.
• the pair of multifocal contact lenses can be any of the pairs described herein.
• each lens of the pair includes a central area that includes the optic axis of the lens and provides substantially all of the distance optical power of the multifocal contact lens.
• Each lens also includes an annular area surrounding the central area. The annular area extends radially outwardly from the central area toward the lens edge. The annular area provides intermediate optical power and near optical power.
• some embodiments of the methods may include providing pairs of contact lenses, wherein the central area of each lens has a spherical surface, and the annular area of each lens has an aspherical surface. Additional or alternative embodiments may provide a pair of contact lenses, wherein each lens of the pair includes only one annular area providing the intermediate optical power and near optical power. In further embodiments, the central area of each lens includes an add power from +0.25 diopters to about +1.25 diopters. [0034] The present lenses are placed on a patient's eye such that the posterior surface of the lens contacts the corneal epithelium of the eye of the patient.
• the present lens pairs it is possible to correct presbyopia of an emerging presbyope without a need to compensate for the patient's add power, without the need to determine eye dominance, or both.
• the present lenses can provide enhanced binocular visual acuity at far, intermediate, and near distances compared to monovision systems.
• an emerging presbyope's vision can be improved so long as the add power provided by the multifocal contact lenses is not greater than 1.25 diopters.
• the present lenses do not provide the desired vision correction, and instead, such patients requiring more than 1.25 diopters of add power show better vision correction using two different multifocal contact lenses, such as a lens pair consisting of a first lens having a distance central area surrounded by an aspheric annular area, and a second lens having a near central area surrounded by an aspheric annular area.
• the present pairs of lenses provide benefits in correcting vision of emerging presbyopic patients, the present lenses can also be useful in correcting or improving the vision of other types of patients.
• the present pairs of contact lenses can be useful in correcting vision of patients, including patients younger than 40 years old, who require less than +1.25 diopters of near vision correction.
• the present lenses can provide the desired near vision correction without interfering with distance vision.
• Another aspect relates to methods of producing the present contact lenses.
• a method of producing contact lenses for correcting vision of a person requiring vision correction of +1.25 diopters or less includes a step of forming a pair of multifocal contact lenses.
• the pair of multifocal contact lenses can be any of the pairs described herein.
• each lens of the pair includes a central area that includes the optic axis of the lens and provides substantially all of the distance optical power of the multifocal contact lens.
• Each lens also includes an annular area surrounding the central area. The annular area extends radially outwardly from the central area toward the lens edge. The annular area provides intermediate optical power and near optical power.
• some embodiments of the methods may include forming pairs of contact lenses, wherein the central area of each lens has a spherical surface, and the annular area of each lens has an aspherical surface. Additional or alternative embodiments may form a pair of contact lenses, wherein each lens of the pair includes only one annular area providing the intermediate optical power and near optical power. In further embodiments, the central area of each lens includes an add power from +0.25 diopters to about +1.25 diopters.
• the forming step can be achieved by a variety of methods.
• the forming includes a step of cast molding each lens of the pair of contact lenses.
• a cast molding method may include providing a female mold section having a concave front curve lens-forming surface, dispensing a polymerizable lens formulation on the concave surface, placing a male mold section having a convex back curve lens-forming surface in contact with the formulation and the female mold section to form a contact lens mold assembly having a contact lens shaped cavity with the formulation provided therein.
• the contact lens mold assembly can be placed in a heated oven to cause the polymerizable lens formulation to polymerize and form a polymerized contact lens product.
• the contact lens mold assembly and formulation located therein can be exposed to other types of polymerizing amounts of radiation, such as ultraviolet radiation and the like.
• the contact lens mold assembly can then be demolded to separate the two mold sections in which the polymerized contact lens remains attached to only one of the mold sections.
• the polymerized contact lens product can be delensed from the mold section and further treated, such as by extracting extractable materials from the lens, hydrating the lens, inspecting the lens, packaging the lens, and sterilizing the lens.
• a molding insert can be machined to include a central spherical surface and an annular aspherical surface.
• the molding insert is used in an injection molding machine to form an injection molded contact lens mold section from a plastic material, such as polypropylene, polystyrene, and the like, which can then be used in the cast molding process to produce the present contact lenses.
• a plastic material such as polypropylene, polystyrene, and the like

Landscapes

• Health & Medical Sciences (AREA)
• Ophthalmology & Optometry (AREA)
• Physics & Mathematics (AREA)
• General Health & Medical Sciences (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Eyeglasses (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=39315409

Family Applications (1)

Country Status (10)

Cited By (2)

Families Citing this family (31)

Citations (4)

Family Cites Families (23)

• 2007
  • 2007-07-30 US US11/830,520 patent/US20090033864A1/en not_active Abandoned
  • 2007-12-17 CN CN200780100591A patent/CN101802683A/zh active Pending
  • 2007-12-17 CA CA2695121A patent/CA2695121A1/en not_active Abandoned
  • 2007-12-17 MX MX2010001166A patent/MX2010001166A/es not_active Application Discontinuation
  • 2007-12-17 WO PCT/US2007/087736 patent/WO2009017516A1/en not_active Ceased
  • 2007-12-17 KR KR1020107004352A patent/KR20100050525A/ko not_active Withdrawn
  • 2007-12-17 BR BRPI0721844-3A2A patent/BRPI0721844A2/pt not_active IP Right Cessation
  • 2007-12-20 EP EP07024694A patent/EP2028528A1/en not_active Withdrawn
  • 2007-12-21 TW TW096149558A patent/TW200905250A/zh unknown
  • 2007-12-21 JP JP2007341893A patent/JP2009031725A/ja active Pending

Patent Citations (4)

Also Published As

Similar Documents

Legal Events