Manufacture of visual lenses
AssigneePilkington Diffractive Lenses Limited
InventorsMichael H. Freeman, Colin M. Perrott
Life of this patent
Estimating the term…
Abstract
A consumable laser mask for forming a visual lens, especially a contact lens, in which at least a portion of the light passing through the lens is focussed by diffractive means. The laser mask is shaped to provide the diffractive means in the finished lens, and is made from a polymeric material with a thickness such that no residue is left at the completion of the laser ablation process. The invention also includes a method of manufacturing a lens using a consumable laser mask in accordance with the present invention.
Claims8
A method of making contact lenses and intra-ocular lenses in which at least a portion of the light passing through the lens is focussed by diffractive means, which method comprises placing the back surface of a consumable mask directly in contact with the lens, the mask having a pattern surface shaped to provide the diffractive means in the finished lens, and exposing the lens and mask to pulses from a laser for a time sufficient to ablate the consumable mask so that as the mask is ablated the lens is eroded in accordance with the pattern on the mask pattern surface.
Dependencies are inferred from the claim text.