EyeLink Eye Tracker and Software FAQs
Welcome to our Frequently Asked Questions page. Here, you will find answers to common questions about our EyeLink eye-tracking hardware and software. Browse through the categories below to find information on everything from EyeLink system to advanced data analysis techniques. If you cannot find your answer, please do not hesitate to contact our support team for further assistance.
Purchase FAQs
For standard systems, we typically ship within one week from receipt of purchase order. Delivery times may vary slightly depending on your location.
Please contact our sales team for prices:
- +1-613-271-8686 x1
- +1-866-821-0731 x1
We work with all major couriers
For sales handled by our Ottawa office, we ship from Ontario, Canada.
Yes, any data collected with the eye tracker and software is stored locally. No data is transmitted to SR Research Ltd.
There is a two year parts and labor warranty on all SR Research manufactured products. Extended warranties can be purchased.
General FAQs
There are many factors that need to be taken into consideration when choosing an eye tracker. Our quiz is a great place to start, and our experienced sales team can discuss your research requirements in detail and help determine the most appropriate solution.
Our analysis software, Data Viewer, is a powerful solution for visualizing and processing gaze data recorded with EyeLink eye trackers. It is available for Windows, macOS, and Linux.
EyeLink data files can also be imported directly to Matlab and R, allowing users to develop custom analysis pipelines.
Finally, EyeLink data can be converted to ASCII format using a free conversion utility, giving users even more options for integrating the data into their preferred analysis tools and workflows.
All EyeLink eye trackers can sample binocularly at 1000 Hz. High sampling rates reduce velocity noise, allowing for increased temporal precision in critical eye tracking measures such as fixation duration and saccade onset. For research into fixational eye movements, such as microsaccades, high sampling rates are critical.
Yes – glasses generally do not present a problem, and small adjustments during participant setup (such as altering the angle at which the camera views the eye) are normally all that is required to ensure excellent data quality. The exception is bifocal or varifocal glasses, as the lens construction can cause issues for pupil detection.
Soft contact lenses do not present any issues, but hard contact lenses can change position as the eye moves, and are not trackable.
Both Experiment Builder and Data Viewer are compatible with macOS
We can provide comprehensive training and installation services, specifically tailored to you and your team’s research goals. Contact sales@sr-research.com for a quote.
Our Support Forum also contains helpful Video Tutorials, Getting Started Guides, Webinars, FAQs and many other useful learning resources, all designed for users who do not have experience with eye tracking.
All EyeLink systems come with a lifetime of free technical support. Our Support Service is outstanding, with a team of highly experienced eye tracking specialists ready to answer any questions you may have about our hardware and software. Our team can provide rapid and invaluable input at every stage of your eye tracking research, from advising on experimental design and implementation, through to analysing and interpreting eye tracking data.
Our Support Forum also contains a wealth of information, including Getting Started Guides, Video Tutorials, Webinars, FAQs and much much more.
Eye Tracker Hardware FAQs
For any research involving touchscreens, the two best options are to
1) Use the 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”. This configuration provides a completely clear, unobstructed view of the eye, allowing the participant to interact with the screen naturally without the participant’s hand and arm blocking the eye tracker’s view. The Tower mount also has a large trackable range, allowing participants to be closer to the screen.
2) Use the EyeLink 3:
This head mounted combined eye and head tracker will allow the participant to touch the screen without interfering with either the eye or head tracking.
For the majority of tasks any computer monitor will do. However, choosing the right display is important for experiments that rely on precise timing, such as gaze-contingent paradigms. We provide a list of monitors that we have tested, and found to have excellent timing properties, on our Support Forum.
Key Specifications to Consider
When selecting a monitor, two specifications are particularly important for minimizing display latency.
- Refresh Rate (Hz): This is the number of times the screen updates per second. For tasks with rapid display changes, a monitor with a refresh rate of 120 Hz or higher is recommended to reduce the time between screen updates.
- Response Time (ms): This measures how quickly a pixel can change from one color to another (often gray-to-gray). A faster response time means the image appears more quickly and with less motion blur. Look for the lowest response time possible (ideally < 2 ms).
Variable Refresh Rate (VRR): Technologies like GSYNC and FreeSync are designed for gaming and can cause timing issues in scientific presentations. You should determine if your stimulus software is compatible with these features. Always check the monitor’s documentation. The best performance for refresh rate and response time may only be achievable with specific resolutions, cables, and settings.
If you have any questions, please contact support@sr-research.com.
Generally, standard ambient room lighting is optimal for eye tracking.
EyeLink systems operate in the infrared (IR) spectrum, so equipment that emits strong or pulsating infrared light can interfere with the EyeLink system’s ability to track the eye. Avoid direct sunlight and use blinds if using the system in rooms with windows.
Ambient lighting can directly affect the size of a participant’s pupils. If you are measuring pupil size, it is advised to keep the ambient light level the same both within a single recording session and across all sessions for a given study. It is also important to ensure the display brightness remains consistent between the calibration/validation phase and the actual stimulus presentation.
People with astigmatism can typically be tracked without issues, but the shape of the cornea may result in a more limited trackable range of eye movements.
For most research scenarios, monocular (tracking one eye) is sufficient, as in healthy participants the other eye will be looking at the same location on the screen.
There are, however, research scenarios in which the ability to record binocularly is critical.
- Vergence / Ocular Disparity: Measuring how the eyes converge / diverge when viewing stimuli at different depths.
- Microsaccades: Many algorithms used to detect these tiny eye movements are optimized for binocular data.
- Clinical populations (e.g., patients with nystagmus): Differences between the two eyes may be informative.
Accurately citing the hardware used in your research is crucial for ensuring reproducibility and providing transparency regarding your experimental setup and methods. Current (7th edition) APA guidelines for citing hardware and specific examples for referencing SR Research EyeLink products are provided below.
In text:
Gaze was recorded monocularly at 1000 Hz with a desktop mounted EyeLink 1000 Plus (SR Research Ltd., 2013) running version 5.50 of the Host Software.
In reference section:
SR Research Ltd. (2013). EyeLink 1000 Plus. [Apparatus and software]. https://www.sr-research.com/eyelink-1000-plus/
For further examples, please see our citation guidelines page.
Imagine two lines extending from the center of your eye to the outer edges of an object you are looking at; the angle between those two lines is the visual angle that the object subtends.
Our website features a more detailed discussion of visual angle, along with a helpful online calculator for converting between pixels and degrees.
Blog Post: What is Visual Angle?
Online Visual Angle Calculator
Blog Post: What is Visual Angle?
EyeLink systems use degrees of visual angle per second as its fundamental unit for calculating eye velocity, which is used to determine the onset and offset of saccades and fixations.
All EyeLink eye trackers have very high spatial accuracy—typically around 0.25–0.5 degrees of visual angle—and excellent precision, often reaching <0.01–0.02 degrees RMS. Detailed specifications can be found on the relevant product pages and in the product brochures (EyeLink 1000 Plus, EyeLink Portable Duo, and EyeLink 3)
The EyeLink Portable Duo and EyeLink 1000 Plus both have distinct head fixed and head free eye tracking modes. Whether or not to use head-stabilization depends on the nature of the participants being tracked, and the task they are performing. In general, head free tracking is most commonly used when the research involves infants, children or patients. Head supports are generally used when accuracy is critical, such as reading research.
Absolutely. Our eye trackers are designed for effortless setup — participants can be positioned and calibrated in just a minute or less. With our intuitive stimulus-presentation software, Experiment Builder, even first-time users can create sophisticated eye-tracking tasks with ease. And when it’s time to analyze results, Data Viewer streamlines the entire process, making visualization and interpretation of eye tracking data fast, and remarkably simple.
Yes – for research with infants, an arm-mounted EyeLink 1000 Plus is perfect, as the infants can be seated comfortably (in a car seat or on their parent’s lap) and the eye tracker / screen adjusted to suit them. We supply a special IR illuminator for research involving infants < 12m.
The EyeLink Portable Duo can be used with children of all ages, but is not suitable for infants < 12m.
Yes – our systems can be integrated with most EEG / MEG / fNIRs and MRI devices. We provide detailed information for specific integrations on our Hardware Integration page. If your particular device is not listed, we can still likely provide a solution. Simply contact us and we will get back to you.
Experiment Builder Software FAQs
Yes – Experiment Builder can present text, images, audio or video files, all with outstanding temporal precision. All stimuli are imported into Experiment Builder via its Library Manager feature.
Experiment Builder is extremely powerful and flexible stimulus presentation software. It can be used to create everything from basic tasks that simply present a sequence of images, videos or texts, to highly complex tasks involving gaze-contingent displays, multiple phases, complex randomization, performance contingent progress, conditional branching and much more.
You can find a list of example templates on our Support Forum.
Yes – you can use Experiment Builder to create and run behavioral experiments that do not require an EyeLink eye tracker. All behavioral data (e.g. keypress responses / reaction times) can be logged to a results file for subsequent analysis.
Experiment Builder requires a license to run, but all updates to Experiment Builder are free, and can be downloaded from our Support Forum. We always recommend that users run the most recent version available.
Experiment Builder comes with many built-in templates that are very easy to adapt and modify. We also have a Video Tutorial Series, Webinars and FAQs on our Support Forum, along with many other Experiment Builder templates. Finally, our outstanding Support Team are always ready to help with any issues or questions that arise.
Any modern Windows PC will be more than capable of running the vast majority of Experiment Builder tasks, but the exact specifications for a Display PC will depend to some extent on the experimental tasks you will be running. For example, gaze-contingent studies and studies involving high resolution video may require more computing power and higher-end video hardware than simple cognitive paradigms.
We provide a more detailed specification list for a stimulus display PC on our Support Forum
Experiment Builder is compatible with macOS, but while computers running macOS can be used for task development, due to recent changes in how macOS handles display timing, we do not currently recommend using them for data collection.
Yes – it is easy to transfer Experiment Builder projects between Windows and macOS.
SR Research Ltd. (2024*). Experiment Builder (Version 2.6.11**) [Computer software]. SR Research Ltd. https://www.sr-research.com/experiment-builder/
*Change to the year of use / version release.
**Change to the Experiment Builder version number used for your study.
Please see our citation guidelines page for further guidance.
No – Experiment Builder uses a simple and intuitive graphical user interface, which is very easy to learn. Tasks are created by linking together basic components to create sequences, which can be nested to allow for looping. We provide many example templates that can be adapted, and have many more examples of specific tasks on our Support Forum.
Experiment Builder supports all SR Research EyeLink eye tracking systems (including legacy systems) and can be used to create behavioral tasks that do not involve eye tracking. It has features that allow for synchronization with a wide range of other biometric recording devices. Experiment Builder will not interface with eye tracking devices made by other manufacturers.
Experiment Builder can synchronize with external devices via TTL or TCP/IP communication, and we provide several example templates which illustrate the various approaches. For more details please see our Support Forum.
Absolutely. Sequences can be nested in order to allow for trial and block level looping, and conditional triggers allow the experimental flow to be precisely controlled.
Yes – Experiment Builder has very sophisticated options for randomization, including multiple blocking levels (with blocks of trials being randomized or running in a fixed order), randomization of trials within blocks, and even run length control (so that, for example, no three trials of a specific type appear consecutively). In addition, multiple trial “lists” can be created, and chosen when the task starts, to allow between-participant manipulations / randomization to be handled.
For text stimuli, Experiment Builder will automatically generate IAs for each of the words presented. This automatic IA generation for text is highly configurable – for example delimiter characters can be used to segment text into Interest Areas at the phrase or sentence or even character level.
For stimuli such as images, Experiment Builder supports rectangular, ellipse and freehand Interest Areas.
Yes – Experiment Builder has a Test Run feature, which allows you to thoroughly pilot your task before committing to collecting data. In addition, the Dummy Mode preference can be checked to allow the task to be tested without having a connection to an EyeLink Host PC.
Experiment Builder automatically writes Data Viewer integration messages to the EyeLink Data File (EDF) allowing Data Viewer to present the relevant background stimuli (text, images or movies) and Interest Areas at the analysis stage.
Data Viewer Software FAQs
Our Support Forum contains a large number of learning resources for Data Viewer, including:
- Getting Started with Data Viewer: This post contains essential information for new users.
- Webinars: These provide deep dives into specific topics and advanced data analysis approaches.
- Getting Started with Data Viewer: This post contains essential information for new users.
- Data Viewer Video Tutorials: This tutorial series is a great way to learn the basics and see the software in action.
No. All upgrades are free.
When citing specialist software in your research, it’s important to follow a consistent format. According to APA guidelines, the general format for citing software is:
Author. (Year). Name of the software (Version number) [Computer software]. Publisher. URL.
For specific Data Viewer examples, please see our citation guidelines page.
We have lots of training resources for Data Viewer on our Support Forum, including Video Tutorials, Webinars and FAQs. Our outstanding Support Team are always ready to help with any issues or questions that arise.
Data Viewer runs on Windows 10/11 (64-bit), macOS (Intel and Apple Silicon) and Linux
Data Viewer outputs reports that contain a wide range of metrics::
- Trial Reports – common trial level metrics include average fixation count, average fixation duration, average saccade amplitude, and average pupil size.
- Fixation Reports – with common metrics including the Duration, Location, Average Pupil Size, and Interest Area Label of each fixation.
- Saccade Reports – common metrics include Saccade Direction, Amplitude, Latency, Start and End x,y and Peak Velocity.
- Interest Area Reports – including standard measures such as Dwell Time, Run Count, Fixation Count, First Fixation Time. More complex metrics include Fixation Sequence Analysis.
- Sample Reports – sample level metrics include the x,y gaze pixel coordinates, Pupil Size, IA Label, and variables that code whether each sample is in a saccade, fixation or blink.
- Time Series (binning) Reports – group sample level data into bins – perfect for analysing data collected with Visual World tasks.
Absolutely. Data Viewer exports all reports as Tab-delimited .txt files which can easily be imported into Excel, R, SPSS or the analysis tool of your choice.
Most labs use Data Viewer to preprocess the gaze data, then run final statistics in R, Python, SPSS, or MATLAB on the output reports that Data Viewer generates.
Yes. Data Viewer includes:
- Rectangle, ellipse and polygon (freehand) IAs
- Static and Dynamic IAs
- Interest Area Reports (which can include many common IA variables such as Dwell Time, Fixation Count, Run Count and much more)
Yes. It can export high-quality gaze overlay images or videos for publications or presentations. In addition to showing fixations and saccades (scan paths), users can also create static and dynamic heat maps, and “bee swarm” animations.
Yes. In addition to our Support Forum resources, our Support Team is on hand to answer any questions you may have about Data Viewer.
No – we provide a free EDF to ASCII conversion tool, and EDF files can also be read directly into Matlab, R and Python.
Yes. Data Viewer is specifically designed to work with multiple EyeLink Data Files, and can handle large numbers of trials, long recording durations and large participant groups.
WebLink Software FAQs
WebLink is ideal for any eye tracking task in which participant behavior is the primary determinant of what happens on screen. WebLink is most often used to record gaze while participants
- Use a web browser
- Read pdf documents
- Interact with software
- Interact with devices such as gaming consoles / tablets
WebLink is also great for implement simple image / video based tasks, as well as questionnaire tasks.
No. WebLink uses a very simple drag and drop user interface that is very easy to learn. Many screen recording tasks simply involve dropping a couple of components onto the timeline and configuring some preferences.
WebLink is Windows only.
WebLink currently supports Chrome and Firefox browsers.
Yes. In addition to our Support Forum resources, our Support Team is on hand to answer any questions you may have about WebLink
WebLink can display images, videos, pdf files and has a range of standard questionnaire components (e.g. Likert scale / Radio buttons etc).
Yes. WebLink is an excellent solution for recording gaze in Unity environments. Please see our Getting Started with WebLink and Unity post on our Support Forum
Yes, WebLink can log all mouse clicks, mouse position and key strokes. The responses to questionnaire components are logged automatically.
Yes. WebLink’s Screen Recording component is perfect for situations in which you want to record gaze while participants interact with software.
Yes. WebLink can record from a webcam / any device that appears as a camera to the Windows operating system. The recording is synchronized with the gaze data, and can be played back in our analysis software, Data Viewer.