08-27-2020, 03:20 PM
You can use any EyeLink system with a touchscreen, but you need to consider the physical setup to avoid blocking the camera's view.
The main issue to be aware of is occlusion—the participant's hand and arm can block the eye tracker's view when they reach out to touch the screen.
1) Use the EyeLink 3:
This head mounted combined eye and head tracker will allow the participant to touch the screen without intefering with either the eye or head tracking. See our website for more details about the EyeLink 3.
2) Use the EyeLink 1000 or EyeLink 1000 Plus with a Tower Mount.
This setup positions the camera and illuminator above the participant, who views the monitor through a "hot mirror" (a special mirror that reflects infrared light but allows visible light to pass through). This configuration provides a completely clear, unobstructed view of the eye, allowing the participant to interact with the screen naturally. The Tower mount also has a large trackable range, making it more comfortable for participants to be closer to the screen.
Note for Experiment Builder Users
Touchscreens are typically treated like standard mouse devices by the operating system. If you're creating your experiment in Experiment Builder, you can simply use mouse triggers to register participant responses on the touchscreen.
The main issue to be aware of is occlusion—the participant's hand and arm can block the eye tracker's view when they reach out to touch the screen.
- For Desktop/Arm Mounts (EyeLink 1000, 1000 Plus, Portable Duo): The participant's reach can easily block the camera's view of the eye or the path of the infrared illuminator.
- For the EyeLink II: The participant's arm can block the head-tracking sensors on the headband. While these sensors can be repositioned, avoiding occlusion may be difficult depending on your setup.
1) Use the EyeLink 3:
This head mounted combined eye and head tracker will allow the participant to touch the screen without intefering with either the eye or head tracking. See our website for more details about the EyeLink 3.
2) Use the EyeLink 1000 or EyeLink 1000 Plus with a Tower Mount.
This setup positions the camera and illuminator above the participant, who views the monitor through a "hot mirror" (a special mirror that reflects infrared light but allows visible light to pass through). This configuration provides a completely clear, unobstructed view of the eye, allowing the participant to interact with the screen naturally. The Tower mount also has a large trackable range, making it more comfortable for participants to be closer to the screen.
Note for Experiment Builder Users
Touchscreens are typically treated like standard mouse devices by the operating system. If you're creating your experiment in Experiment Builder, you can simply use mouse triggers to register participant responses on the touchscreen.