This article answers frequently asked questions about outdoor eye tracking and sunlight mitigation techniques.
What Performance Can I Expect Outdoors?
As a general rule, eye tracking is more challenging in sunlight conditions than in an indoor environment. While there have been advancements in using eye trackers in direct sunlight, users will most likely have a better experience in the shade. Users can expect even better performance indoors, as that environment offers optimal conditions for eye tracking. It’s also important to note that performance differences may vary between individuals.
What Can I Do to Ensure the Best Possible Performance Outdoors?
To optimize eye tracker performance outdoors, try to avoid glare, reflections, low screen visibility, and forcing the user to squint to see the screen. If you find yourself in direct sunlight, you can try wearing a baseball cap, a wide-brimmed hat, non-mirrored / slightly-tinted sunglasses, or any other headwear that casts shade over your eyes. It is best to avoid having the sun beam straight into the eye tracker, which prevents the device from clearly seeing the user’s eyes. Positioning the eye tracker so that it faces away from the sun or shielding it with a sunbrella will yield better results. See below for a link to a recommended sunbrella.
What is the Optimal Position Outdoors?
For optimal performance outdoors, position yourself and the device away from the sun. If the user’s eyes are shaded so the eye tracker can see them, the user can face the sun. The least favorable position outdoors is when the sun shines directly into the eye tracker.
Can I Use the Same Calibration Outdoors and Indoors?
Yes, the same calibration can be used both outdoors and indoors. However, many users will benefit from having two separate calibrations for indoor and outdoor environments. Because your pupils dilate and contract in different lighting conditions, their appearance can change significantly when moving between environments. You may experience a significant gain in accuracy by creating separate calibrations for the two different settings.
Can I Use Sunglasses When Eye Tracking?
Yes, most sunglasses can be used as long as the lenses are not mirrored and appear translucent. If you experience eye tracking issues, try removing the sunglasses to see if the frames or lenses are causing the problem.
Does Outdoor Eye Tracking Affect Power Consumption?
Using an eye tracker outside does not consume more power. However, keep in mind that operating in very bright environments will require higher screen backlight (brightness) intensity, which can affect tablet battery consumption.
Do You Recommend a Specific Sunbrella?
We recommend the Versa-Brella from Sport-Brella, which can be found here: Versa-Brella with Universal Clamp.
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