FAQ: *The Corneal Reflection keeps jumping, what is going wrong?

[SR-SUPPORT]

If the tracker is losing the corneal reflection (CR) or if the CR is jumping to incorrect locations / switching between two different locations, it's usually because the camera is detecting multiple sources of infrared (IR) light or because the image thresholds are set incorrectly.

Here are the steps to resolve this issue.

• Check for External IR Sources
  First, ensure there are no other sources of infrared light in front of the participant. Common culprits include:
  • Sunlight from a window
    
  • Security cameras
    
  • Other IR-emitting devices
    
• Check Your Hot Mirror
  If you are using a hot mirror, it must be a first-surface (or front-surface) mirror. A standard, second-surface mirror will create multiple IR reflections that will confuse the tracker.
  
• Adjust Search Limits for Glasses
  If the participant is wearing glasses, reflections from the frames can sometimes be mistaken for the CR. You can prevent this by adjusting the Search Limits (the red ellipse) to create a tighter boundary around the eye, excluding any reflections from the glasses.
  
• Verify Image Thresholds
  If you have eliminated all extra IR sources, the final step is to ensure the camera image is properly thresholded. A correct threshold setting is critical for isolating the pupil and the true corneal reflection.