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Eye Tracking Environments

All vision based systems, such as eye tracking, are sensitive to environmental parameters. Just like eyesight, low light, strong backlight or occlusions can heavily impact the systems ability to detect and track objects. Obital's eye tracking is no exclusion.

Typical Environmental Challenges

Parameter Description Solution Impact (low-high)
Low light Indoors with no external light, or night time. Inform the user that the system works best under normal light conditions. 🟡
Strong backlight Strong sources of light (such as the sun) directly behind the user. Inform the user that they should avoid strong backlight 🟡
Vibrations Occurs if the device is held with shaky hands, or placed on a surface with vibrations Inform the user 🔴
Wrong positioning The user places the iPad in extreme angles or distances to the device Use the trackbox supplied by Obital 🟢
Calibration deterioration Face pose changes, device drift and more Make sure a calibration session does not last for too long, give the user the option to recalibrate, or force recalibration occasionally 🟢
Glasses Glasses may distort the eye image. Is only a problem in special cases - for example if the glasses are reflective, shades, or extremely warped. Let the user try the system to determine if the glasses impacts the experience. 🟢
Occlusions Hands in front of the face, masks etc. Heavy occlusions can completely block face detection. If the occlusion is permanent, the system may not work. If it's temporary, the system will return to normal once removed All views supplied by Obital automatically informs the user if the system is unable to detect the face. 🔴
Drowsy eyes People with naturally (or intentionally) drowsy eyes may experience issues as the eyelids cover the pupil Use the eyeLidState (planned feature) to inform the user of potential problems 🟡
Eye disabilities Diseases and disabilities that impacts the eye aestethics or mobility Impact heavily depends on the disability. We recommend pre-screening users in a tutorial or similar to assess their ability to use their eyes. 🟡

Best Practices to Avoid Environmental Challenges

As can be seen in the table above, some challenges are easily solvable, while others require some kind action from the user. We recommend that you:

  1. Inform the user of possible challenges and optimal conditions before starting a session.
  2. Screen user's eye movements before moving to the actual application. One way could be to have the user complete a tutorial or onboarding that requires some kind of eye interaction. If the user is unable to complete it, it may be related to unsolvable environmental factors.
  3. React to system updates about possible issues. Always use the built-in trackbox.

Troubleshooting Environmental Challenges

See troubleshooting for more information.

If you or a user has a suspicion about environmental factors impacting performance, using the SessionStatusViewController can help identifiying possible issues. If the face stays undetected for a longer period, a view controller displaying the video feed is displayed. Inspecting the feed can help identifiy possible issues.