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Blinks
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- Blinks (EyeLink I, II, 1000, 1000 Plus, Portable Duo):
SBLINK <eye > <stime>
EBLINK <eye > <stime> <etime > <dur>
- Blinks (EyeLink 3):
SBLINK <eye> <stime> <hissx> <hissy> <hisex> <hisey> <hisax> <hisay> <eihsx> <eihsy> <eihex> <eihey> <eihax> <eihay> <hrsx> <hrsy> <hrsz> <hrex> <hrey> <hrez> <hrax> <hray> <hraz> <hpsx> <hpsy> <hpsz> <hpex> <hpey> <hpez> <hpax> <hpay> <hpaz>
EBLINK <eye> <stime> <etime> <dur> <hissx> <hissy> <hisex> <hisey> <hisax> <hisay> <eihsx> <eihsy> <eihex> <eihey> <eihax> <eihay> <hrsx> <hrsy> <hrsz> <hrex> <hrey> <hrez> <hrax> <hray> <hraz> <hpsx> <hpsy> <hpsz> <hpex> <hpey> <hpez> <hpax> <hpay> <hpaz>
For both the start and end events of the EyeLink 3 data,
- the head tracking data (<hrsx> <hrsy> <hrsz> <hrex> <hrey> <hrez> <hrax> <hray> <hraz> <hpsx> <hpsy> <hpsz> <hpex> <hpey> <hpez> <hpax> <hpay> <hpaz>) can be disabled by passing in the "-nht" switch when running the conversion from the command prompt or enable the "EyeLink 3 -> Blocking Head Tracking Output" option from "Preferences".
- the extended eye/head position data (<hissx> <hissy> <hisex> <hisey> <hisax> <hisay> <eihsx> <eihsy> <eihex> <eihey> <eihax> <eihay>) can be disabled by passing in the "-ned" switch when running the conversion from the command prompt or enable the "EyeLink 3 -> Blocking Extended Eye Position" option from "Preferences".
Blinks (periods of data where the pupil is missing) are reported by the SBLINK and EBLINK lines. The time of the start of the blink is indicated by the SBLINK line, which can be eliminated by blocking the start event. The <eye> is "L" or "R", indicating the eye's data that produced the event. The end and duration are given in the EBLINK event.
Blinks are always embedded in saccades, caused by artifactual motion as the eyelids progressively occlude the pupil of the eye. Such artifacts are best eliminated by labeling and SSACC...ESACC pair with one or more SBLINK events between them as a blink, not a saccade. The data contained in the ESACC event will be inaccurate in this case, but the <stime>, <etime>, and <dur> data will be accurate.
It is also useful to eliminate any short (less than 120 millisecond duration) fixations that precede or follow a blink. These may be artificial or be corrupted by the blink.
Data notations:
| Field | Content |
| <eye > | which eye caused event ("L" or "R") |
| <time > | timestamp in milliseconds |
| <stime > | timestamp of first sample in milliseconds |
| <etime > | timestamp of last sample in milliseconds |
| <dur > | duration in milliseconds |
| <axp > <ayp > | average X and Y position |
| <sxp > <syp > | start X and Y position data |
| <exp > <eyp > | end X and Y position data |
| <aps > | average pupil size (area or diameter) |
| <av > <pv > | average, peak velocity (degrees/sec) |
| <ampl > | saccadic amplitude (degrees) |
| <xr > <yr > | X and Y resolution (position units/degree) |
| <hissx > <hissy > | X, Y head position in screen pixel coordinates when the event starts |
| <hisex > <hisey > | X, Y head position in screen pixel coordinates when the event ends |
| <hisax > <hisay > | Average X, Y head position in screen pixel coordinates |
| <eihsx > <eihsy > | Participant's eye pose in relation to the head, without head-movement contribution, represented as a gaze point on the screen (X, Y in screen pixel coordinates) when the event starts |
| <eihex > <eihey > | Participant's eye pose in relation to the head, without head-movement contribution, represented as a gaze point on the screen (X, Y in screen pixel coordinates) when the event ends |
| <eihax > <eihay > | Average rotation of the eye within the head along the X- and Y-axis (in screen pixel coordinates) |
| <hrsx > <hrsy > <hrsz > | Rotation angle (in degrees) of the head around the X-axis (pitch), the Y-axis (yaw), and the Z-axis (roll) when the event starts. |
| <hrex > <hrey > <hrez > | Rotation angle (in degrees) of the head around the X-axis (pitch), the Y-axis (yaw), and the Z-axis (roll) when the event ends. |
| <hrax > <hray > <hraz > | Average rotation angle (in degrees) of the head around the X-axis (pitch), the Y-axis (yaw), and the Z-axis (roll). |
| <hpsx > <hpsy > <hpsz > | Translational movements along the X, Y, and Z axes when the event starts. |
| <hpex > <hpey > <hpez > | Translational movements along the X, Y, and Z axes when the event ends. |
| <hpax > <hpay > <hpaz > | Average translational movements along the X, Y, and Z axes. |