AIM: To compare the cup-to-disc ratio (CDR) and optic disc morphology between eyes with congenital cataract and eyes without cataract in children under 3 years old. METHODS: This study included 63 patients with bilateral congenital cataract (mean age of 55.72±46.50wk, 44 were male), 33 patients with unilateral cataract (mean age of 56.63±33.23wk, 16 were male), and 31 age-matched healthy children (mean age of 55.80±29.29wk, 17 were male). Fundus photographs were taken with the RetCam 3 system. The horizontal-to-vertical disc diameter ratio (HVDR) was used as an index to describe the oval form of the optic disc. RESULTS: The horizontal cup-to-disc ratio (HCDR), vertical cup-to-disc ratio (VCDR) and HVDR of cataract eyes in unilateral groups were significantly smaller than those of the normal eyes (P<0.05). In the unilateral group, the HCDR, VCDR and HVDR of cataract eyes were significantly smaller than those in fellow eyes (P<0.05). The HVDR of eyes in the bilateral group was significantly smaller than those in the age-matched normal eyes (P<0.001). The form of optic disc of the cataract eyes in both the bilateral and unilateral groups was more vertical-oral than the normal eyes in the unilateral and the age-matched groups (P<0.05). CONCLUSION: Our results show that eyes with congenital cataract has a smaller HVDR and the form of the optic disc tended to be vertical-oval in young children.