This study was approved by the University of California San Francisco Institutional Review Board and followed the principles of the Declaration of Helsinki. Adult subjects gave informed written consent to participate. Minors expressed verbal assent and a parent provided formal informed consent.
The 27 subjects who wore the eye tracking glasses included the 4 authors, their professional colleagues, family members, friends, and neighbors. Most individuals wore the glasses as a favor or because they were curious about our research. There was no organized recruitment strategy. All subjects had normal visual function. In some subjects, this was verified by an ophthalmological screening examination, including the assessment of acuity, pupils, eye movements, and stereopsis. For others, we relied on the subject's assurance that their vision was normal. No participant had strabismus, corneal disease, nystagmus, prior eye surgery, or cervical spine disease. Most subjects were recorded without refractive correction. Individuals with a large refractive error were corrected with spherical equivalent lenses that fit into the glasses frames or wore their contact lenses.
The 27 subjects were asked to wear the eye tracking glasses for as long as convenient while engaged in their regular, daily activities. Subjects removed the eye tracking glasses when using the bathroom. The device resumed tracking with no loss of calibration when placed back on the head.