231 abbreviations
Abbreviation Meaning
TBUT Tear break-up time
Tc Centre thickness
TD Total diameter
tds/tid Three times a day
Te Edge thickness
TIA Transient ischaemic attack
TWT/WTT Today wearing time
Tx Treatment
ung Ointment
V Vision (unaided)
VA Visual acuity (corrected)
VA OD Right visual acuity
VA OS Left visual acuity
VDU Visual display unit
VF Visual field
VPA Vertical palpebral aperture
VPS Variable prism stereoscope
Vx Vomiting
WD Working distance
WEHE Welsh Eye Health Examination
WLVS Welsh Low Vision Service
WT Wearing time
X/12 X months
X/52 X weeks
X/7 X days
XP Exophoria
XT Exotropia
Δ Prism dioptre
θ Vertical orthophoria
ϕ Horizontal orthophoria
Horizontal and vertical orthophoria