Photochromic vehicle window

1. A vehicle window assembly, comprising:

a photochromic window; and

a mounting assembly surrounding at least part of the window, the mounting assembly sized and configured for mounting to the cabin of a vehicle,

wherein the photochromic window includes a first photochromic region configured to change transmission of a light in a frequency range by a first percentage, a second photochromic region configured to change transmission of the light in the frequency range by a second percentage, wherein the first percentage is smaller than the second percentage, and at least one photochromic region displaced between the first and second photochromic regions, the at least one photochromic region being configured to change transmission of the light in the frequency region by a percentage greater than the first percentage but smaller than the second percentage.

2. The window assembly of claim 1 , wherein the frequency range includes at least one of a visible spectrum of light, an infrared spectrum of light, or an ultraviolet spectrum of light.

3. The window assembly of claim 1 , wherein the frequency range includes a visible spectrum of light.

4. The window assembly of claim 1 , wherein the frequency range includes an infrared spectrum of light.

5. The window assembly of claim 1 , wherein the frequency range includes an ultraviolet spectrum of light.

6. The window assembly of claim 1 , wherein the window is at least one of a windshield, a rear window, a door window, or a roof window.

7. The window assembly of claim 1 , wherein the window is a roof window comprising over 75% of the surface area of a roof of the cabin.

8. The window assembly of claim 1 , wherein changing the transmission of the light includes at least one of absorption or reflection of the light.

9. The window assembly of claim 1 , wherein the photochromic window includes microcrystalline silver halides and the level of light includes an intensity of ultraviolet light.

10. The window assembly of claim 1 , wherein the region is smaller than the total surface area of the photochromic window.

11. A vehicle cabin window, comprising:

a window pane sized and configured for mounting to a cabin of a vehicle;

a first photochromic region configured to change transmission of an infrared spectrum of light, or an ultraviolet spectrum of light by a first percentage;

a second photochromic region configured to change transmission of the infrared spectrum of light or the ultraviolet spectrum of light in the frequency range by a second percentage, wherein the first percentage is smaller than the second percentage; and

at least one photochromic region displaced between the first and second photochromic regions, the at least one photochromic region being configured to change transmission of the light in the frequency region by a percentage greater than the first percentage but smaller than the second percentage.

12. The window of claim 11 , wherein the frequency range includes a visible spectrum of light.

13. The window of claim 11 , wherein the frequency range includes an infrared spectrum of light.

14. The window of claim 11 , wherein the frequency range includes an ultraviolet spectrum of light.

15. The window of claim 11 , wherein the window at least one of a windshield, a door window, or a roof window.

16. The window of claim 11 , wherein the window is a roof window comprising over 75% of the surface area of a roof of the cabin.

17. The window of claim 11 , wherein changing the transmission of the light includes at least one of absorption or reflection of the light.

18. The window of claim 11 , wherein the level of light includes an intensity of ultraviolet light.

19. The window of claim 11 , wherein changing transmission of the light by the first percentage includes changing a transmittance of the light in the frequency range through the window from greater than 90% to less than 50%.