Assertion: acceleration | /r/CapableOf | lie on their back
Facets:
value: essentially
type: DEGREE
Source sentences:
text: In general when the acceleration is forwards (subject essentially lying on their back, colloquially known as "eyeballs in"), a much higher tolerance is shown than when the acceleration is backwards (lying on their front, "eyeballs out") since blood vessels in the retina appear more sensitive in the latter direction.[citation needed]