Table 2.

Causes of poor eyesight (visual acuity worse than 6/12)

	Unilateral poor eyesight	Bilateral poor eyesight*	Total*
Causes	No (%)‡	No (%)‡	No (%)
Refractive errors
myopia +/− astigmatism*	24 (0.96)	117 (4.66)	141 (5.62)
hyperopia +/− astigmatism	7 (0.28)	3 (0.12)	10 (0.40)
astigmatism only	2 (0.08)	1 (0.04)	3 (0.12)
refractive error and amblyopia†	3 (0.12)	4 (0.16)	7 (0.28)
Subtotal	33 (1.31)	121 (4.82)	154 (6.13)
Anterior segment
corneal scar	3 (0.12)	0 (0.00)	3 (0.12)
cataract	1 (0.04)	0 (0.00)	1 (0.04)
aphakia and amblyopia	0 (0.00)	1 (0.04)	1 (0.04)
Subtotal	4 (0.16)	1 (0.04)	5 (0.20)
Posterior segment
optic atrophy*	3 (0.12)	4 (0.16)	7 (0.28)
optic nerve coloboma	1 (0.04)	0 (0.00)	1 (0.04)
retinopathy or maculopathy or macular scars	6 (0.24)	0 (0.00)	6 (0.24)
Subtotal	10 (0.40)	4 (0.16)	14 (0.56)
Others
strabismic amblyopia	1 (0.04)	0 (0.00)	1 (0.04)
phthisis	1 (0.04)	0 (0.00)	1 (0.04)
Subtotal	2 (0.08)	0 (0.00)	2 (0.08)
Total	49 (1.95)	125 (4.98)	174 (6.93)

*One student had bilateral myopia and optic atrophy and has been included under both conditions, but only once in the total.

†These individuals are also included under the appropriate refractive error, but only once in the total.

‡Percentage of all students (n = 2511).