| Tobii Pro SDK C API
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| Data Fields | |
| float | diameter | 
| TobiiResearchValidity | validity | 
Provides properties for the pupil data.
| float TobiiResearchPupilData::diameter | 
The diameter of the pupil in millimeters.
| TobiiResearchValidity TobiiResearchPupilData::validity | 
The validity of the pupil data.