Blue light adjustment for biometric identification

1. A head mounted display system configured to provide variable levels of blue light to an eye of a user, the display system comprising:

a frame configured to be wearable on the head of the user;

a display configured to project at least blue light into the eye of the user and to modify an intensity of the blue light relative to an intensity of non-blue light;

a camera configured to capture a first image of the eye while the display projects light at a first ratio of intensity of blue light to non-blue light into the eye and configured to capture a second image of the eye while the display projects a second ratio of intensity of blue light to non-blue light different from the first ratio into the eye; and

a hardware processor programmed to:

analyze the images from the camera to determine whether a change in a pupil parameter between the second image and the first image passes a biometric application threshold;

based at least in part on the determined change, instruct the display to modify a ratio of the intensity of blue light to non-blue light and instruct the camera to capture a third imam of the eye;

determine that a change in the pupil parameter between the third image and the first image or the second image passes a biometric application threshold; and

perform a biometric application in response to the determination that the change in the pupil parameter between the third image and the first image or the second image passes a biometric application threshold.

2. The head mounted display system of claim 1 , wherein the display is configured to modify the intensity of blue light in a wavelength range of between 445 nm and 525 nm.

3. The head mounted display system of claim 1 , wherein the hardware processor is programmed to increase a number of pixels of the display projecting blue light during the first image relative to the number of pixels of the display projecting blue light during the second image.

4. The head mounted display system of claim 1 , wherein the display is configured to display content as if at a plurality of depths from a user.

5. The head mounted display system of claim 1 , wherein the display comprises a scanning fiber projector.

6. The head mounted display system of claim 1 , wherein the display is configured to present a light field image to the user.

7. The head mounted display system of claim 1 , wherein the system comprises a plurality of stacked waveguides.

8. The head mounted display system of claim 7 , wherein to instruct the display to modify the intensity of blue light relative to non-blue light, the hardware processor is programmed to instruct an image injection device to increase a ratio of blue light injected into a corresponding stacked waveguide of the plurality of stacked waveguides.

9. The head mounted display system of claim 1 , wherein the pupil parameter comprises at least one of a maximum radius of the pupil, a minimum radius of the pupil, a rise time of a pupillary response to the second ratio of intensity of blue light to non-blue light, a decay time of a pupillary response to the second ratio of intensity of blue light to non-blue light, and a delay time of a pupillary response to the second ratio of intensity of blue light to non-blue light.

10. The head mounted display system of claim 1 , wherein the pupil parameter comprises a circumference of the pupil.

11. The head mounted display system of claim 1 , wherein the change in the pupil parameter comprises at least one of a rise curve for a rise time of a pupillary response to the second ratio of intensity of blue light to non-blue light and a decay curve for a decay time of the pupillary response to the second ratio of intensity of blue light to non-blue light.

12. The head mounted display system of claim 1 , wherein the biometric application comprises at least one of generating an iris code, determining a cognitive response, authorizing access to the head mounted display system, identifying the user of the head mounted display system, displaying information associated with an individual associated with a determined pupillary response, and determining a physiological state of the user of the head mounted display system.

13. The head mounted display system of claim 1 , wherein the hardware processor is programmed to present, during a start-up of software for the head mounted display system, an image that changes in intensity of blue light.

14. The head mounted display system of claim 13 , wherein the hardware processor is programmed to measure a change in the pupil parameter during the start-up of the software, and perform a biometric identification action.

15. The head mounted display system of claim 14 , wherein performing the biometric identification action comprises at least one of identifying the user of the display system, determining that the user of the display system is a living individual, determining that the user of the display system is authorized to use the display system, and displaying information that is associated with an individual having the measured change in pupil parameter.

16. A method for adjusting a level of blue light exposed to an eye using a wearable display system comprising a camera coupled to computing hardware, the wearable display system comprising a stack of waveguides configured to direct light into the eye, the method comprising:

directing reference light comprising a first ratio of an intensity of blue light to an intensity of non-blue light into the eye;

using the camera, capturing a first image of the eye while the reference light is directed into the eye;

directing modified light comprising a second ratio of an intensity of blue light to an intensity of non-blue light different from the first ratio into the eye;

using the camera, capturing a second image of the eye while the modified light is directed into the eye;

detecting a change in a pupil parameter of the eye between the second image and the first image;

determining that the detected change in the pupil parameter passes a biometric application threshold;

based at least in part on the determination, modifying a ratio of the intensity of blue light to non-blue light;

using the camera, capturing a third image of the eye;

determining that a change in the pupil parameter between the third image and the first image or the second image passes a biometric application threshold; and

performing a biometric application in response to the determination that the change in the pupil parameter between the third image and the first image or the second image passes a biometric application threshold.

17. The method of claim 16 , wherein directing modified light into the eye comprises increasing the intensity of blue light relative to the reference light.

18. The method of claim 17 , wherein increasing the intensity of blue light comprises flashing blue light for longer than 10 ms.

19. The method of claim 16 , wherein detecting the change in the pupil parameter of the eye between the second image and the first image comprises comparing a pupil radius of the first image to a pupil radius of the second image, wherein determining that the detected change in the pupil parameter passes the biometric application threshold comprises determining that a difference in the pupil radius exceeds the biometric application threshold.

20. The method of claim 16 , further comprising determining that an image quality metric measured from the first image exceeds an image quality threshold, the image quality metric comprising a distance between a part of the eye and an eyelid.