Prevalence of Heterophoria in Tibetan Grade-One Students: The Lhasa Childhood Eye Study

Table 3

Prevalence of heterophoria, orthophoria, and heterotropia for grade-one pupils at near and distance fixation.

	Distance (n, %)	Near (n, %)
Heterophoria	86 (4.64)	421 (22.73)
Exophoria	78 (4.21)	414 (22.35)
Esophoria	8 (0.43)	7 (0.38)
Vertical phoria	0 (0.00)	0 (0.00)
Orthophoria	699 (91.74)	1364 (73.65)
Heterotropia	67 (3.62)	67 (3.62)