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EP-4468066-B1 - CONTACT LENSES

EP4468066B1EP 4468066 B1EP4468066 B1EP 4468066B1EP-4468066-B1

Inventors

  • CHEN, CHIH-CHENG
  • LIAO, HSIEN-SHENG
  • YANG, WEN-CHI

Dates

Publication Date
20260506
Application Date
20230526

Claims (8)

  1. A contact lens (10), comprising: a first optical region (20) located in a central region of the contact lens (10), the first optical region (20) being shaped to form a first power profile (202) with a negative power; a second optical region (30) surrounding the first optical region (20), the second optical region (30) being shaped to form a second power profile (302) with a positive power relative to the first optical region (20); and a transition region (40) joined between the first optical region (20) and the second optical region (30), the transition region (40) being shaped to form a third power profile (402) with a power variation radially changing from the first power profile (202) to the second power profile (302) as a radius increasing, wherein the transition region (40) comprises a first subzone (41) joining to the first optical region (20), a second subzone (42) joining to the first subzone (41) and a third subzone (43) joined between the second subzone (42) and the second optical region (30), each of the first subzone (41) and the third subzone (43) has a gradual power variation measured from a lens center (101) to a lens edge (103) as compared to the second subzone (42), and the second subzone (42) has a steep power variation measured from the lens center (101) to the lens edge (103); wherein the first subzone (41), the second subzone (42) and the third subzone (43) satisfy the following relationships: 35 % ≤ W 1 W total ≤ 45 % 15 % ≤ W 2 W total ≤ 25 % 35 % ≤ W 3 W total ≤ 45 % 8.3 % ≤ ΔP 1 ΔP total ≤ 25 % 58.3 % ≤ ΔP 2 ΔP total ≤ 75 % 8.3 % ≤ ΔP 3 ΔP total ≤ 25 % wherein W1, W2 and W3 represent an annular ring width of the first subzone (41), the second subzone (42) and the third subzone (43), respectively, W total represents an annular ring width of the transition region (40), ΔP1, ΔP2 and ΔP3 represent the power variation of the first subzone (41), the second subzone (42) and the third subzone (43) along a radius direction as the radius increasing, respectively, and Δ P total represents a total power variation of the transition region (40) along the radius direction as the radius increasing; characterized in that the annular ring width (W total ) of the transition region (40) ranges from 0.3 mm to 1.4 mm.
  2. The contact lens (10) of claim 1, wherein the first subzone (41) has a first subzone power profile with a curvilinear or curve ramp configuration, the second subzone (42) has a second subzone power profile with a sloped ramp configuration, and the third subzone (43) has a third subzone power profile with a curvilinear or curve ramp configuration.
  3. The contact lens (10) of claim 1 or 2, wherein the first power profile (202) and the second power profile (302) are substantially constant powers with increasing radius, respectively.
  4. The contact lens (10) of any of the preceding claims, wherein the first optical region (20) is shaped to have a first radius of curvature ranging from 7.05 mm (millimeters) to 12.05 mm on an outer surface (12) of the contact lens (10).
  5. The contact lens (10) of any of the preceding claims, wherein the second optical region (30) is shaped to have a second radius of curvature ranging from 6.8 mm to 11.0 mm on an outer surface (12) of the contact lens (10).
  6. The contact lens (10) of any of the preceding claims, wherein the transition region (40) is shaped to have a third radius of curvature ranging from 6.5 mm to 10.5 mm on an outer surface (12) of the contact lens (10).
  7. The contact lens (10) of any of the preceding claims, wherein each of the first subzone (41), the second subzone (42) and the third subzone (43) provides a progressively increasing power as the subzones extend radially outwardly, wherein the power variation of the second subzone (42) is greater than the power variations of the first subzone (41) and the third subzone (43).
  8. The contact lens (10) of any of the preceding claims, wherein the first subzone (41) has a first rate of change in power/radius, the second subzone (42) has a second rate of change in power/radius, and the third subzone (43) has a third rate of change in power/radius, wherein the second rate of change is larger than either of the first rate of change or the third rate of change.

Description

FIELD OF THE INVENTION The present disclosure relates to a contact lens, and more particularly to a peripheral defocus contact lens with controlled optical power profile to balance abrupt power variation between the central and the peripheral regions. BACKGROUND OF THE INVENTION Contact lenses are widely used to correct defects in vision, such as myopia, hyperopia, astigmatism, presbyopia, etc. Conventional contact lenses provide a vision-correcting curvature only in an optical region at the center of a lens so that the image focus is moved to the retina to correct the vision, and a peripheral region around the first optical region is used to support the lens to fit the shape of a user's eyeball. While lenses with a peripheral region with an add-power offset relative to the central region of the lens have been demonstrated to suppress myopia progression for some wearers. However, this kind of multizonal lens may cause symptoms such as headache, dizziness and peripheral blurry. US 2010/073629 A1 discloses a contact lens according to the preamble of claim 1, but with different annular ring width. US 2014/320800 A1 discloses a contact lens similiar to that disclosed by US 2010/073629 A1. A related contact lens is disclosed by US2010/036489 A1. SUMMARY OF THE INVENTION In particular, it is an object of the present invention to provide an enhanced contact lens, in particular a peripheral defocus contact lens, configured to alleviate discomfort problems of wearers, such as headache, dizziness and peripheral blurry and related symptoms. This problem is solved by a contact lens as claimed in claim 1. Further advantageous embodiments are the subject-matter of the dependent claims. According to the present invention the multifocal contact lens combines different radii of curvature of multiple optical regions on one contact lens. For example, a first optical region is for correcting myopia and a second optical region is for correcting presbyopia, such that the wearer may switch between two different types of corrections quickly and also maintain clear vision when looking at near or distant objects. An additional optical region or subzone may be provided to alleviate a change from the optical power of the first optical region to the optical power of the second optical region and also to balance abrupt power variation of the second subzone, when the wearer's eye orients from the first optical region to the second optical region. As a result, symptoms, such as headache, dizziness, peripheral blurry and other discomfort-symptoms of the wearer can be alleviated. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a contact lens of the present disclosure;FIG. 2 is a plan view of a contact lens according to a first embodiment of the present disclosure;FIG. 3 is a cross-section view of the lens of FIG. 2 taken along line A-A of FIG. 2;FIG. 4 illustrates the power profile as the function of the radial distance from the center of the contact lens in accordance with the first embodiment of the present disclosure;FIG. 5 is a plan view of a contact lens according to a second embodiment of the present disclosure;FIG. 6 is a cross-section view of the lens of FIG. 5 taken along line B-B of FIG. 5; andFIG. 7 illustrates the power profile as the function of the radial distance from the center of the contact lens in accordance with the second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present disclosure provides a contact lens to prevent or slow progression of myopia, hyperopia or presbyopia with improved comfort. As used herein, the term "contact lens" refers to an ophthalmic lens that can be placed onto the anterior surface of a person's eye. It will be appreciated that such a contact lens will provide clinically acceptable on-eye movement and not bind to the person's eye. The contact lens may be in the form of a corneal lens (e.g., a lens that rests on the cornea of the eye). The contact lens may be a soft contact lens, such as a hydrogel contact lens or a silicone hydrogel contact lens. Terms used herein are merely based on illustration of specific embodiments and are not intended to limit the present disclosure. As used herein, the singular forms "a", "an", and "the" include the plural forms as well, unless the context clearly indicates otherwise. Detailed description and technical content of the present disclosure are described below with reference to the drawings. The terms "Diopter" or "D" as used herein is the unit measure of dioptric power, defined as the reciprocal of the focal distance of a lens, in meters, along an optical axis. Referring to FIG. 1, a perspective view of a contact lens of the present disclosure is shown. The present disclosure provides a contact lens 10 which includes an inner side surface (a back surface) 11 and an outer surface (a front surface) 12. The inner side surface 11 attaches to a wearer's eye when the contact lens 10 is worn, which ma