High index glass and devices incorporating such

1. A glass comprising: a refractive index N of greater than 1.65 at a wavelength λ, where λ=587.6 nm; a glass density of not more than 4.2 g/cm 3 ; Abbe number V d greater than 30; the glass comprising in wt % based on the oxides, with total weight percent adding to 100%:

SiO 2 , 5-45 wt %;

ZrO 2 , 5-9 wt %;

CaO 4.5-16 wt %;

La 2 O 3 1 wt % to 28 wt %;

Nb 2 O 5 0.5 wt % to 20 wt %;

TiO 2 7-20 wt %;

As 2 O 3 0% to 0.15 wt %;

Er 2 O 3 0.03% to 0.25 wt %;

Na 2 O 2-5 wt %;

K 2 O 4-9 wt %;

Sr 0 to 1 wt %;

BaO 10-20 wt %; and

F 0-1 wt %.

2. The glass according to claim 1 , further comprising 0.03 wt % to 0.05 wt % Er 2 O 3 .

3. The glass of claim 1 , said glass comprising Er 2 O 3 in the amount greater than 0.05 wt %.

4. The glass according to claim 1 , comprising 0.05 wt % to 0.1 wt % Er 2 O 3 .

5. A glass comprising: a refractive index N of greater than 1.65 at a wavelength λ, where λ=587.6 nm; a glass density of not more than 4.2 g/cm 3 ; Abbe number V d greater than 30; the glass comprising the following components:

SiO 2 , 40.50 wt %;

ZrO 2 , 8.70 wt %;

Na 2 O 3.11 wt %;

K 2 O 5.85 wt %;

CaO 5.20 wt %;

SrO 0.5 wt %;

BaO 16.30 wt %;

La 2 O 3 1.0 wt %;

Nb 2 O 5 1.30 wt %;

TiO 2 17.07 wt %;

As 2 O 3 0.15 wt %;

F 0.22 wt %, and

Er 2 O 3 0.1 wt %;

and,

wherein the glass has a minimum absorption Amin (%) for a wavelength with a wavelength range of 450 nm to 700 nm, and a maximum Absorption Amax (%) for another wavelength within said wavelength range, and Amax/Amin is at least 2 for at least one glass thickness with a 25 mm to 125 mm range, wherein the total weight percent of the components adds up to 100%.

6. The glass according to claim 1 and further comprising As 2 O 3 0% to 0.05 wt %.

7. The glass of claim 1 , wherein the glass has a maximum internal transmission Tmax (%) for a wavelength with a wavelength range of 450 nm to 700 nm, and a minimum internal transmission Tmin (%) for another wavelength within said wavelength range, and Tmax/Tmin is at least 2 for at least one glass thickness with a 25 mm to 125 mm range.

8. The glass of claim 1 , wherein the glass has a minimum absorption Amin (%) for a wavelength with a wavelength range of 450 nm to 700 nm, and a maximum Absorption Amax (%) for another wavelength within said wavelength range, and Amax/Amin is at least 2 for at least one glass thickness with a 25 mm to 125 mm range.

9. A glass according to claim 1 , wherein glass density is not greater than 4.05 g/cm 3 .

10. The glass according to claim 1 , wherein the refractive index is a refractive index N is 1.65<N≤1.9 at a wavelength λ, where λ=587.6.

11. A wearable device comprising the glass of claim 1 .

12. A lens comprising the glass of claim 1 .

13. A wearable device comprising the lens of claim 12 .

14. The light guide device comprising:

(a) a light guide comprising the glass of claim 1 ;

(b) an input grating being structured and positioned to transmit light of one or more wavelengths to the glass light guide, and

(c) an output grating;

wherein the glass light guide is positioned and structured to transmit light in one or more wavelengths within the glass light guide towards an output grating, along an optical path situated within the glass light guide between the input grating and the output grating and to filter out at least 50% of light in at least one light wavelength λa that propagates toward the output grating.

15. The glass according to claim 1 and further comprising As 2 O 3 concentration in 0% wt % to 0.1 wt % range.

16. A glass having a refractive index of greater than 1.65 at a wavelength λ of, and consisting of, in wt %, based on the oxides, with total weight percent adding to 100%:

SiO 2 , 40.35 wt %;

ZrO 2 , 8.70 wt %;

Na 2 O 3.11 wt %;

K 2 O 5.85 wt %;

CaO 5.20 wt %;

SrO 0.5 wt %;

BaO 16.30 wt %;

La 2 O 3 1.0 wt %;

Nb 2 O 5 1.30 wt %;

TiO 2 17.07 wt %;

As 2 O 3 0.15 wt %;

F 0.22 wt %, and

Er 2 O 3 0.25 wt %;

wherein the glass has a minimum absorption Amin (%) for a wavelength with a wavelength range of 450 nm to 700 nm, and a maximum Absorption Amax (%) for another wavelength within said wavelength range, and Amax/Amin is at least 2 for at least one glass thickness with a 25 mm to 125 mm range.