US 12,072,556 B2
Contact lenses with surfaces having different softness
Yongxing Qiu, Suwanee, GA (US); Robert Carey Tucker, Suwanee, GA (US); and Yeming Gu, Suwanee, GA (US)
Assigned to Alcon Inc., Fribourg (CH)
Filed by Alcon Inc., Fribourg (CH)
Filed on Nov. 3, 2020, as Appl. No. 17/087,963.
Claims priority of provisional application 62/930,163, filed on Nov. 4, 2019.
Prior Publication US 2021/0132411 A1, May 6, 2021
Int. Cl. G02C 7/04 (2006.01); B29D 11/00 (2006.01); B29K 67/00 (2006.01); B29K 83/00 (2006.01); G02B 1/04 (2006.01)
CPC G02C 7/049 (2013.01) [B29D 11/00048 (2013.01); B29D 11/00067 (2013.01); G02B 1/043 (2013.01); B29K 2067/00 (2013.01); B29K 2083/00 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A contact lens, comprising a lens bulk material covered with an outer surface hydrogel layer and having a posterior surface and an opposite anterior surface, wherein the outer surface hydrogel layer consists of an anterior outer hydrogel layer and a posterior outer hydrogel layer, wherein the outer posterior surface hydrogel layer is softer than the outer anterior surface hydrogel layer as characterized by having a ratio of indentation depth ratio,

OG Complex Work Unit Math
of at least about 1.2, wherein (Id)PS is the indentation depth measured with a indenting probe having a tip radius of 9.5 μm and a stiffness of 0.54 N/m at 5 KPa compression pressure against the posterior surface in a nanoindentation test, wherein (id)AS is the indentation depth measured with a indenting probe having a tip radius of 9.5 μm and a stiffness of 0.54 N/m at 5 KPa compression pressure against the anterior surface in a nanoindentation test, wherein the contact lens has a water-break-up time of at least 10 seconds.