Ophthalmic lenses and their manufacture by in-mold modification
The mold assembly with controlled polymerization using a photochemical radiation source allows for the formation of geometric indentations on ophthalmic lenses, addressing uniformity and customization issues in lens design.
Patent Information
- Authority / Receiving Office
- HK · HK
- Patent Type
- Applications
- Current Assignee / Owner
- JOHNSON & JOHNSON VISION CARE INC
- Filing Date
- 2026-06-09
- Publication Date
- 2026-07-17
AI Technical Summary
Existing methods for forming ophthalmic lenses do not effectively create predetermined geometric indentations on the lens surfaces during polymerization, leading to uniformity issues and limitations in customizing lens designs.
A mold assembly comprising a bottom-curved and front-curved mold is used, with a reactive monomer mixture and a first polymerization initiator, where a light-transmitting mold is exposed to a uniform photochemical radiation source to initiate polymerization, allowing for controlled formation of geometric indentations by extracting unreacted portions after curing.
Enables the creation of ophthalmic lenses with predetermined geometric indentations, enhancing design customization and surface profile control.
Smart Images
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Abstract
Description
A method for forming an ophthalmic lens includes providing a mold assembly comprising a bottom-curved mold and an front-curved mold, each having a surface profile and defining and closing a cavity therebetween, the cavity containing a reactive monomer mixture for preparing the lens and a first polymerization initiator activated at a first wavelength. A light-transmitting mold within the mold is exposed at the first wavelength to a substantially uniform photochemical radiation source according to a predetermined exposure pattern comprising at least one exposed portion and at least one unexposed portion to initiate polymerization of the reactive monomer mixture within the mold at said at least one exposed portion. The lens is fully cured at the exposed portion, and unreacted or ungelled portions remain within the lens adjacent to the front and bottom half-molds. These unreacted or ungelled portions are extracted after removal from the mold assembly, thereby leaving one or more predetermined geometric indentations in the front and rear surfaces of the lens, such that the surface profile of the lens deviates from the surface profiles of the respective front and rear half-molds at the location of the geometric indentations.
Claims
We claim:
1. A method for forming an ophthalmic lens, the method comprising:(a) providing a mold assembly including a base curve mold and a front curve mold, each having a surface profile, the base curve mold and the front curve mold defining and enclosing a cavity therebetween, the cavity containing a reactive monomer mixture comprising a monomer suitable for making the ophthalmic lens and a first polymerization initiator that is capable of being activated at a first wavelength, wherein at least one of the base curve mold or front curve mold is light transmissive;(b) exposing the at least one light transmissive base or front curve mold to a source of substantially uniform actinic radiation at the first wavelength according to a predetermined exposure pattern including at least one exposure portion and at least one non-exposure portion to initiate polymerization of the reactive monomer mixture within the mold at said at least one exposure portion;(c) exposing said at least one exposure portion to said source of actinic radiation until the lens is fully cured at said exposure portions;(c) wherein the at least one non-exposure portion is selected such that, upon full curing of the at least one exposure portion, unreacted or non-gelled portions remain within the lens adjacent to the front and base mold halves;(d) removing the ophthalmic lens from the mold assembly; and(e) extracting said unreacted and non-gelled portions to thereby leave one or more predetermined geometric indentations in the front and back surfaces of the lens such that the surface profile of the lens deviates from the surface profile of the respective front and back mold halves at the locations of the geometric indentations.
2. The method according to claim 1 , wherein the source of actinic radiation includes a plurality of selectively controllable beams of actinic radiation and in the at least one exposure portion the plurality of selectively controllable beams direct said actinic radiation onto said transmissive mold half, and in the at least one non-exposure portion the plurality of selectively controllable beams do not direct said actinic radiation onto said transmissive mold half.
3. The method according to claim 1, wherein the source of actinic radiation includes a plurality of selectively controllable beams of actinic radiation and in the at least one exposure portion the plurality of selectively controllable beams direct said actinic radiation onto said transmissive mold half, and in the at least one non-exposure portion the plurality of selectively controllable beams direct said actinic radiation onto said transmissive mold half according to a predetermined gray scale pattern.
4. The method according to claim 3, wherein the plurality of beams of actinic radiation are selectively controlled by a digital micro-mirror device according the predetermined exposure pattern.
5. The method according to claim 4, wherein the digital micro-mirror device includes an illumination source containing at least one light emitting diode.
6. The method according to claim 3, wherein the plurality of beams of actinic radiation are selectively controlled by a static mask with a predetermined exposure pattern.
7. The method according to claim 3, wherein the plurality of beams of actinic radiation are selectively controlled by a static mask with a predetermined exposure pattern which includes regions of partial transmission8. The method according to claim 1, wherein the first wavelength is in the range of 380 to 450 nm.
9. The method according to claim 8, wherein the first wavelength is approximately 420 nm.
10. The method according to claim 1, wherein the ophthalmic lens is a hard contact lens, a soft contact lens, a hybrid contact lens, a rigid gas permeable contact lens, or an intraocular lens.
11. The method according to claim 1, wherein following the extraction step the fully cured lens includes at least one recess at a front and back surface of the lens.
12. The method according to claim 11, wherein the at least one recess further comprises a plurality of substantially round recesses.
13. The method according to claim 12, wherein the plurality of substantially round recesses are placed in at least one predetermined portion of the lens, and wherein said predetermined portion has a different surface friction than the remainder of the lens.
14. The method according to claim 11, wherein the at least one recess further comprises a longitudinal channel.
15. The method according to claim 1, wherein following the extraction step the fully cured lens include at least one fenestration through the lens extending between the front and back surface of the lens.
16. A method for forming an ophthalmic lens, the method comprising:(a) providing a mold assembly including a base curve mold and a front curve mold, each having a surface profile, the base and front curve molds defining and enclosing a cavity therebetween, the cavity containing a reactive monomer mixture comprising a monomer suitable for making the ophthalmic lens, a first polymerization initiator that is capable of being activated at a first range of wavelengths, and a UV blocker, wherein at least one of the base or front curve molds is light transmissive;(b) exposing the at least one light transmissive base or front curve molds to a source of substantially uniform actinic radiation at a first wavelength within said first range according to a predetermined exposure pattern, including at least one primary exposure portion and at least one secondary exposure portion, to initiate polymerization of the reactive monomer mixture within the mold at said at least one primary exposure portion, wherein said primary exposure portions are exposed to said first wavelength until the lens is fully cured at said primary exposure portions;(c) exposing the at least one light transmissive base or front curve molds at said at least one secondary exposure portions to a source of substantially uniform actinic radiation at a second wavelength that is at least partially attenuated by said UV blocker to initiate polymerization of the reactive monomer mixture within the mold assembly, wherein exposure at said secondary exposure portions is at a predetermined time and intensity so as not to fully cure the lens at said secondary exposure portions;(d) removing the ophthalmic lens from the mold assembly; and(e) extracting uncured and non-gelled portions from the lens to thereby leave one or more predetermined geometric indentations in the front or back surface of the lens such that the surface profile of the lens deviates from the surface profile of the respective front or back curve molds at the locations of the geometric indentations.
17. The method according to claim 16, wherein the source of actinic radiation includes a plurality of selectively controllable beams of actinic radiation that direct said actinic radiation onto said transmissive front or back curve mold when in an “on” position and do not direct said actinic radiation onto said transmissive front or back curve mold when in an “off’ position.
18. The method according to claim 17, wherein the plurality of beams of actinic radiation selectively controlled by a digital micro-mirror device according the predetermined exposure pattern.
19. The method according to claim 18, wherein the digital micro-mirror device includes an illumination source containing at least one light emitting diode.
20. The method according to claim 17, wherein the plurality of beams of actinic radiation are selectively controlled by a static mask with a predetermined exposure pattern which includes which includes regions of partial transmission21. The method according to claim 16, wherein the first range of wavelengths is 380 to 450 nm.
22. The method according to claim 21 , wherein the first wavelength is approximately 420 nm.
23. The method according to claim 22, wherein the second wavelength is approximately 365 nm.
24. The method according to claim 16, wherein the ophthalmic lens is a hard contact lens, a soft contact lens, a hybrid contact lens, a rigid gas permeable contact lens, or an intraocular lens.
25. The method according to claim 16, wherein following the extraction step the fully cured lens includes at least one recess at a front or back surface of the lens.
26. The method according to claim 25, wherein the plurality of substantially round recesses are placed in at least one predetermined portion of the lens, and wherein said predetermined portion has a different surface friction than the remainder of the lens.
27. The method according to claim 25, wherein the at least one recess further comprises a longitudinal channel.