09-04-2020, 03:28 PM
Participants with astigmatism can typically be calibrated and tracked, but due to the shape of the eye, the corneal reflection may be lost or distorted when the gaze position nears the extremities of the trackable range (for instance, one or both of the top corners of the monitor). If the tracking is lost or distorted at one of the top corners of the monitor, try moving the Desktop mount towards that side of the monitor in 1 - 2 cm increments until the eye can be reliably tracked at all four corners of the screen and recalibrate the participant. Alternatively, or if no such position can be found for that participant, you can switch to using the 5-point (HV5) calibration if it’s not critical that the corners of the screen be calibrated.
It is worth noting that if there is a frequent lost of tracking or difficulty calibrating one or both top corners of the screen, these problems are most likely due to issues in the physical setup between the camera, Display monitor, and participant. Try re-positioning the Display screen further from the participant so it falls within the trackable range, or lower the screen / raise the participant so that their eyes are in line with the top 25% of the Display monitor.
Please see the relevant Video Tutorials for detailed advice on how to ensure your system is set up correctly.
It is worth noting that if there is a frequent lost of tracking or difficulty calibrating one or both top corners of the screen, these problems are most likely due to issues in the physical setup between the camera, Display monitor, and participant. Try re-positioning the Display screen further from the participant so it falls within the trackable range, or lower the screen / raise the participant so that their eyes are in line with the top 25% of the Display monitor.
Please see the relevant Video Tutorials for detailed advice on how to ensure your system is set up correctly.
- EyeLink 1000 Plus Setup and Usage Training Videos
- EyeLink Portable Duo Setup and Usage Video Tutorials