Optical article comprising an antireflective coating with a low reflection both in the ultraviolet region and in the visible region

1. An ophthalmic lens comprising a transparent substrate with a front main face and a rear main face, said rear main face being coated with a multilayered antireflective coating comprising a stack of at least one layer having a refractive index higher than 1.6 and of at least one layer having a refractive index lower than 1.55, wherein:

a mean reflection factor R UV on said rear face between 280 nm and 380 nm, weighted by a function W(λ), is lower than or equal to 5%, for an angle of incidence of 35°; and

a Chroma C* of reflected light for an angle of incidence (θ) of 15° is equal or lower than 4, and

wherein said antireflective coating is substantially achromatic.

2. The lens according to claim 1 , wherein the mean reflection factor R UV on said rear face between 280 nm and 380 nm, weighted by the function W(λ), is lower than or equal to 4%, for an angle of incidence of 35°.

3. The lens according to claim 1 , wherein the Chroma C* of reflected light for an angle of incidence (θ) of 15° is lower or equal to 3.

4. The lens according to claim 1 , wherein the Chroma C* of reflected light for an angle of incidence (θ) of 15° is located in the area of a L*a*b* space defined by:

−3<=a*<=1 and −4<=b*<=1 and (a*+b*)>=−5.

5. The lens according to claim 1 , wherein the Chroma C* of reflected light measured on two separated points of the same lens differs by less than 2.

6. The lens according to claim 1 , wherein the multilayered antireflective coating comprises a number of layers higher than or equal to 3 and lower than or equal to 7.

7. The lens according to claim 6 , wherein the multilayered antireflective coating comprises a number of layers higher than or equal to 4 and lower than or equal to 6.

8. The lens according to claim 1 , wherein the mean reflection factor on said rear face in a visible region R m is lower than or equal to 3%, for an angle of incidence lower than or equal to 35°.

9. The lens according to claim 8 , wherein the mean reflection factor on said rear face in the visible region R m is lower than or equal to 2.5%, for an angle of incidence lower than or equal to 35°.

10. The lens according to claim 1 , wherein the mean light reflection factor on said rear face in a visible region R v is lower than or equal to 2%, for an angle of incidence lower than or equal to 35°.

11. The lens according to claim 10 , wherein the mean light reflection factor on said rear face in the visible region R v is lower than or equal to 1.5%, for an angle of incidence lower than or equal to 35°.

12. The lens according to claim 1 , wherein the antireflective coating is deposited on a silica-based sub-layer layer having a thickness of from 100 to 300 nm.

13. The lens according to claim 1 , wherein the antireflective coating comprises at least two layers having a refractive index higher than 1.6 and at least two layers having a refractive index lower than 1.55.

14. The lens according to claim 1 , wherein the antireflective coating comprises at least one electrically conductive layer.

15. The lens according to claim 1 , wherein the antireflective coating comprises, in the direction moving away from the substrate, a layer having a refractive index higher than 1.6 with a thickness of from 8 to 25 nm, a layer having a refractive index lower than 1.55 with a thickness of from 15 to 40 nm, a layer having a refractive index higher than 1.6 with a thickness of from 80 to 115 nm, optionally an electrically conductive layer with a thickness of from 3 to 10 nm, and a layer having a refractive index lower than 1.55, with a thickness of from 65 to 95 nm.

16. The lens according to claim 15 , wherein the antireflective coating comprises, in the direction moving away from the substrate, a layer having a refractive index higher than 1.6 with a thickness of from 8 to 25 nm, a layer having a refractive index lower than 1.55 with a thickness of from 15 to 40 nm, a layer having a refractive index higher than 1.6 with a thickness of from 85 to 110 nm, optionally an electrically conductive layer with a thickness of from 3 to 10 nm, and a layer having a refractive index lower than 1.55, with a thickness of from 65 to 95 nm.

17. The lens according to claim 15 , wherein the antireflective coating comprises, in the direction moving away from the substrate, a layer having a refractive index higher than 1.6 with a thickness of from 10 to 18 nm, a layer having a refractive index lower than 1.55 with a thickness of from 25 to 35 nm, a layer having a refractive index higher than 1.6 with a thickness of from 95 to 110 nm, optionally an electrically conductive layer with a thickness of from 3 to 10 nm, and a layer having a refractive index lower than 1.55, with a thickness of from 75 to 85 nm.

18. The lens according to claim 15 , wherein the antireflective coating comprises, in the direction moving away from the substrate, a layer having a refractive index higher than 1.6 with a thickness of from 18 to 25 nm, a layer having a refractive index lower than 1.55 with a thickness of from 15 to 25 nm, a layer having a refractive index higher than 1.6 with a thickness of from 85 to 95 nm, optionally an electrically conductive layer with a thickness of from 3 to 10 nm, and a layer having a refractive index lower than 1.55, with a thickness of from 70 to 90 nm.

19. The lens according to claim 1 , wherein said ophthalmic lens is substantially achromatic.