Tobii Eye Trackers

Last modified by Iris Spruit on 2024/04/16 09:41
Contents

Introduction

Tobii Pro eye trackers are used to measure eye movement and pupil size. 

Availability, support and advice

A Tobii eye tracker can be borrowed from SOLO through the Helpdesk. Note that only a limited amount of eye trackers is available. The Tobii eye trackers are supported by SOLO, for questions please contact labsupport@fsw.leidenuniv.nl.

Software

Tobii Eye Trackers can easily be used with Tobii software, such as Tobii Pro Lab. To incorporate Tobii eye tracking in other stimulus presentation software, see for example the E-Prime and Tobii and OpenSesame and Tobii pages. See for more information about Tobii software the Tobii software guide and What software and operating systems are compatible with Tobii eye trackers? for an overview of system and software compatibility for all Tobii eye trackers.

Eye tracker setup

How the eye tracker is set-up depends on the eye tracker model. See below for more information on the specific model. For questions,  contact labsupport@fsw.leidenuniv.nl. When using a Tobii Pro remote eye tracker (e.g. Fusion, X3-120, X2-60, Nano) the eye tracker needs to be configured after connecting it to a computer. This configuration needs to be performed each time the eye tracker is connected to another computer. See the Eye Tracker Manager for instructions how to configure the eye tracker. Only after this setup, the eye tracker can be used with the desired task presenting software.

Tips & Tricks

Dark and bright pupil tracking. Eye trackers that us Pupil Center Corneal Reflection (PCCR) use two different illumination techniques: Bright pupil tracking and dark pupil tracking (for more information and to see which eye tracker uses which mode, see Dark and Bright pupil tracking (tobii.com)). Important to note is that the X3-120 uses a fixed sequence of pupil tracking: Dark, Dark, Bright, and pupil size is only reported during bright pupil tracking. Therefore, pupil size is only reported in a third of the samples (40 Hz).

Connection loss. Although it does not happen often, it is possible that the connection is lost with the eye tracker during your experiment. When this happens, not all software packages inform you about this.

  • Tobii Pro Lab does not do anything, the task continues and it is not clear that connection was lost during any point of the experiment. It is advised to always shortly inspect your data after collection. Of course, it is not necessary to view the whole recording, but a few parts would be advised.
  • Tobii Studio gives a warning when connection is lost. The task continues, but the warning stays on the screen until it is clicked away. When the task is run without a moderator screen (that is, with only one screen) it will be unclear to the experimenter that the connection is lost, and has to rely on the participant to relay the message.
  • OpenSesame with PyGaze does not do anything, the task continues and it is not clear that connection was lost during any point of the experiment. It is advised to always shortly inspect your data file. When connection is lost, data is not saved to the data file anymore. A quick way to check whether data is missing is to look at the size of your data file. When it is a lot smaller than usual, this could be caused by connection loss.
  • E-Prime with EET and/or TPL package does not do anything, the task continues and it is not clear that connection was lost during any point of the experiment. When using EET and a gazedata file is saved, it is advised to always shortly inspect your data file. When connection is lost, data is not saved to the data file anymore. A quick way to check whether data is missing is to look at the size of your data file. When it is a lot smaller than usual, this could be caused by connection loss. When using EET with TPL and data is saved in Tobii Pro Lab, it is advised to shortly inspect the recording in Tobii Pro Lab after data collection. Of course, it is not necessary to view the whole recording, but a few parts would be advised.

Tobii Pro eye tracker models

A list of Tobii eye tracker models that are (or were) used at FSW Leiden are given below. Note that this is not an exhaustive list of all Tobii Pro eye trackers. For currently available models, see the Tobii Pro website.

Spectrum

Tobii-pro-spectrum-big2.jpg

The Tobii Pro Spectrum is a screen based eye tracker, sampling at 300, 600 or 1200 Hz (depending on the hardware version). The eye tracker comes with a screen, but can be detached from the screen when stimuli are presented without screen. The eye tracker is connected to the PC with a network cable and the eye tracker screen can be connected to the PC with various display connectors. The Spectrum is Tobii's most powerful eye tracker and its usage is recommended in more detailed studies, infant research and it has special modes for eye tracking with apes and monkeys. The FSW has one Spectrum eye tracker (600 Hz) which is part of a fixed setup in an infant lab. For more information, contact labsupport@fsw.leidenuniv.nl. The latest version of the manual and other Spectrum related products can be downloaded here. 

Fusion

Tobii-Fusion.jpg

The Tobii Pro Fusion is a remote screen based eye tracker, sampling at 60, 120, or 250 Hz (250 Hz is not available by default). The bar can be connected to a monitor with a magnetic strip and is connected to the PC via USB. It is recommended to connect the power adapter for best performance. A Fusion eye tracker can be borrowed from SOLO through the Helpdesk. Note that some difficulties have been observed with the Fusion, especially in infant research. For more information, contact labsupport@fsw.leidenuniv.nl. The latest version of the manual and other Fusion related products can be downloaded here.

Nano

TobiiPro_Nano_54712.jpg

The Tobii Pro Nano is a small remote screen based eye tracker, sampling at 60 Hz. The bar can be connected to a monitor with a magnetic strip and is connected to the PC via USB. This eye tracker can only be used with relatively small screens (up to 24"), see the specifications for more info. A Nano eye tracker can be borrowed from SOLO through the Helpdesk. The latest version of the manual and other Nano related products can be downloaded here.

Spark

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The Tobii Pro Spark is a remote screen based eye tracker, sampling at 60 Hz. The bar can be connected to a monitor with a magnetic strip and is connected to the PC via USB. The Spark is Tobii's entry-level eye tracker, which means it is most affordable, but lacks a bit mainly in accuracy and precision compared to the other eye trackers (see the specifications for more info and a comparison with other Tobii eye trackers). The latest version of the manual and other Spark related products can be downloaded here.

Glasses 3

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The Tobii Pro Glasses 3 is a wearable eye tracker. Different sampling at 50 or 100 Hz. Data recordings are controlled by a controller app and data can be analyzed with Tobii Pro Lab (using an Analyzer license). For more information see the short Tobii Pro Glasses 3 Overview video and the Analyzing and understanding Tobii Pro Glasses 3 recordings video. The manual and other Glasses 3 related products can be downloaded here.

X3-120

Tobii X3-120.png

The Tobii Pro X3-120 is discontinued and cannot be purchased anymore. Its successor is the Tobii Pro Fusion.

The Tobii X3-120 is a remote, screen based eye tracker sampling gazedata at 120, but pupil size at 40 Hz (see also My Tobii Pro X3-120 shows pupil size every third sample.). The bar can be connected to a monitor with a magnetic strip and is connected to the PC via an external processing unit (EPU). An X3-120 can be borrowed from SOLO through the Helpdesk. The latest version of the manual and other X3-120 related products can be downloaded here.

When measuring pupil size, E-Prime 2 and EET2 cannot be used in combination with the X3-120 eye tracker. The Tobii X3-120 eye tracker uses bright mode and dark mode to track the eye. The order that the eye tracker uses these modes in is: 1 bright – 2 dark. Pupil size should only be reported during bright mode (this thus results in a sampling rate of pupil size of 40 Hz). However, in combination with E-Prime 2, pupil size is reported in both bright and dark mode. It is unfortunately impossible to know which mode has been used for which sample. The interchangeable use of the two modes causes a lot of noise in the pupil data. In E-Prime 3 the issue is solved and pupil size is only reported during bright mode.

X2-60

Tobii X2-60.png

The Tobii Pro X2-60 is discontinued and cannot be purchased anymore. Its successor is the Tobii Pro Fusion.

The Tobii X2-60 is a remote, screen based eye tracker sampling at 60 Hz. The bar can be connected to a monitor with a magnetic strip an is connected to the PC via a processing unit. The latest version of the manual and firmware can be downloaded here.

T120

Tobii-T120-Eye-Tracker.png

The Tobii T120 is discontinued and cannot be purchased anymore. Due to its age, support for the T120 is limited.

The Tobii T120 is a screen based eye tracker consisting of a screen with built in eye tracker, sampling at 120 Hz. The manual is available here.

Glasses 2

Tobii glasses2.png

The Tobii Pro Glasses 2 is discontinued and cannot be purchased anymore. Its successor is the Tobii Pro Glasses 3.

The Tobii Pro Glasses 2 is a wearable eye tracker, sampling at 50 or 100 Hz. Data recordings are controlled by the Tobii Pro Glasses 2 Controller and data can be analyzed with Tobii Pro Lab (using an Analyzer license). For more information see the Learn how to use Tobii Pro Glasses 2 video. The manual and other Glasses 2 related products can be downloaded here.

Synchronization between Glasses 2 and other equipment

The Glasses 2 can send and receive pulses (TTL triggers) through a sync port, which enables synchronization between the Glasses 2 and other equipment (such as Biopac).

By default, the Glasses 2 sends synchronization pulses. These pulses, which consist of one bit (on or off), start when the recording starts with a sequence consisting of a 500 ms high pulse (3.3 V), followed by a 500 ms low pulse (0 V), repeated 3 times. After that, one pulse is emitted once every ten seconds and has a duration of 1000 ms. See the Glasses 2 User Guide (which can be downloaded here) for more information.

The Glasses 2 can also receive pulses. These pulses also consist of one bit (on or off) and can be sent from stimulus presentation software such as OpenSesame or E-Prime. The pulses are logged as SYNC IN HI and SYNC IN LOW events, as viewed in Tobii Pro Lab.

Sending pulses to the Glasses 2 is generally preferred over sending pulses from the Glasses 2, as it provides more flexibility in determining the timing of the triggers. Please contact labsupport@fsw.leidenuniv.nl for advice on your specific setup and synchronization needs. Labsupport can also provide the necessary cables for synchronization (whether it'd be sending or receiving pulses) and advice on electrical safety when using the sync port. 

HTC Vive Pro Eye with Tobii Eye Tracking

Tobii-HTC-Vive-VR-Headset.png

The Vive Pro Eye is a VR headset that can be integrated with Tobii eye tracking. More information can also be found here.

FAQ

DateTopicSolution
 Tobii eye tracker cannot be found by any software on the PC

Restart the eye tracker:

  • Switch off the eye tracker.
  • Disconnect the eye tracker.
  • Reconnect the eye tracker.
  • Switch back on the eye tracker.
  • If an SR Eyelink has been used, a fixed IP address will have been set on the network adapter. This needs to be changed back to dynamic to work with Tobii. 
 X3-120 or X2-60 cannot be found by any software on the PC 
  1. Restart EPU:
    • Switch off EPU.
    • Disconnect the power cord.
    • Reconnect the power cord.
    • Switch on EPU. 
       
  2. Check cables: USB cable from eye tracker bar to EPU and the ethernet cable from EPU to PC.

    For the X3-120 the USB cable can be replaced, labsupport has them in stock. The USB cable of the X2-60 cannot be replaced, as it is attached to the eye tracker bar. If the issue seems to be related to the USB cable of an X2-60, the eye tracker needs to be sent to Tobii for repairs.

    Note: When the Eye Tracker Manager or Browser is only showing the EPU number (starting with EPU instead of e.g. X3-120) it is fairly likely that the USB cable between the EPU and eye tracker bar is the issue. This can further be tested by plugging in the eye tracker bar directly into the PC. When the USB cable is fine, the eye tracker should appear in the Manager or Browser. Finally, replacing the USB cable (if possible) should provide a further answer.
     
  3. Happened once with a X3-120 eye tracker: The firmware version of the eye tracker bar was different than the firmware of the EPU. Unknown how this happened. Could be fixed by Tobii with remote session.
     
 Tobii eye tracker is not found by Tobii Eye Tracker Browser, Tobii Pro Studio and E-Prime 2
  1. Check if Tobii eye tracker can be found in Tobii Eye Tracker Manager.
     
  2. If the eye tracker is found in the Eye Tracker Manager, reinstall Bonjour 2.0.2.0 (admin rights required, contact labsupport for installations on lab PC's). If the eye tracker is not found in the Eye Tracker Manager, check the solutions mentioned above.

Note 1: The newer generations of Tobii eye trackers (e.g. Tobii Fusion) are not compatible with the Tobii Eye Tracker Browser and Tobii Pro Studio.

Note 2: When Tobii Pro Studio or E-Prime 2 does not need to be used, one can just use the Eye Tracker Manager for setting up the eye tracker (screen alignment). Connection with Tobii Studio, the Browser, and E-Prime 2 is not necessary for an eye tracker to function with other software packages.
 

 E-Prime gives error that the Tobii eye tracker cannot be found
  1. Check whether the correct eye tracker number is specified in E-Prime:
    Go to Edit ⇒ Experiment ⇒ Devices ⇒ TobiiEyeTracker. In E-Prime 3, the eye tracker can be specified in the Eye Tracker drop-down menu. In E-Prime 2, the eye tracker serial number needs to be looked up in the Eye Tracker Browser, then copied and pasted in the IP Address/Name field in the TobiiEyeTracker device in E-Prime.
     
  2. Check whether the eye tracker can be found in the Eye Tracker Manager (E-Prime 3) or Browser (E-Prime 2) and check the solutions above.
     
 OpenSesame gives error "AttibutionError eyetracker object (t0) not found"
  1. Check the serial number. The serial number should be specified in an inline at the beginning of the task:

    from pygaze import settings
    settings.TRACKERSERIALNUMBER = "X3120-XXXXXXXXXXXX"

    The serial number of the eye tracker can be found in the Eye Tracker Manager.
     
  2. If serial number is correct, try running the task again. For reasons unknown, this error just pops up from time to time.
     
  3. Check connection with eye tracker in the Eye Tracker Manager . If the eye tracker is not found in the Eye Tracker Manager, check the solutions mentioned above.
 In the Eyetracker Manager the X2-60 eye tracker cannot be mapped to the screen (three dots greyed out and not clickable).Check if the firmware of the EPU needs an update. This can be checked and updated in the Eye Tracker Browser. The latest firmware can be downloaded here. Old firmware does not allow mapping through the Eye Tracker Manager. 
 

Tobii Pro Lab gives error when trying to start the calibration:

Someting went wrong.

Something went wrong when communicating with the eye tracker. If the error persists, please try restarting the eye tracker and the application.

Make sure the eye tracker is mapped to the screen by doing the Display Setup in the Eye Tracker Manager.

Restart the eye tracker and Tobii Pro Lab.

 Connect Fusion to USB at the back of the PC

When using the power adapter for the USB extension cable:

After restarting the PC the PC did not want to boot anymore, it gave a bios error. This was caused by the power adapter providing power to the PC through the USB cable. Using the USB 3 port at the backside of the PC fixed the issue.

Resources

   
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