Lens precursor with features for the fabrication of an ophthalmic lens
This invention provides for the fabrication of ophthalmic lenses via the utilization of DMD shows and/or DMD files. More specifically, the use of the DMD shows and/or DMD files to generate lens precursor designs comprising described features to form part of a substructure for the fluid reactive media portion of the lens precursor and wherein the lens precursor can generate particular ophthalmic lens designs in a free-form manner using methods described herein.
1. A lens precursor form comprising:
a concave, optical quality first surface;
an opposing second surface having a substantially convex overall shape;
wherein the first and second surfaces are joined at a lens edge, wherein the lens edge defines the outer perimeter of the lens precursor form; and
a plurality of drain channel features, each comprising an elongate depression extending in a radial direction toward the lens edge, the drain channel features being placed side by side and configured to enable the flow of fluent lens reactive media across the lens precursor form.
2. The lens precursor form of claim 1 in which each drain channel feature is a continuous depression.
3. The lens precursor form of claim 1 in which each drain channel feature comprises discrete segmented depressions.
4. The lens precursor form of claim 1 in which the drain channel features radiate from a particular region of the lens precursor form so as to draw fluent lens reactive media away from that region.
5. The lens precursor form of claim 4 in which the drain channel features radiate in substantially all directions.
6. The lens precursor form of claim 4 in which the drain channel features radiate in a limited number of directions, thereby forming a fan-shaped drain sector.
7. The lens precursor form of claim 6 in which the fan-shaped drain sector has an included angle of between 2 and 360 degrees, for example between 30 and 120 degrees or between 60 and 90 degrees.
8. The lens precursor form of claim 7 in which the drain channel features further comprise circumferential drain channels at or towards their outer ends, at or towards their inner ends, or elsewhere, or in any combination of positions.