Purpose:To investigate ambylopia and amblyopia risk factors of children who underwent nasolacrimal duct (NLD) irrigation and probing for congenital nasolacrimal duct obstruction (CNLDO).Materials and Methods:The medical records of patients who had undergone NLD irrigation and probing for CNLDO at an age of 3 years or younger were reviewed, and 51 of the patients were recalled between October 1 and December 31, 2011 for a detailed ophthalmic examination to determinate amblyopia or amblyopia risk factors. Amblyopia was accepted as difference in visual acuity of two or more Snellen lines between the two eyes or visual acuity of 20/30 or worse in either eye.Results:The median age of the 51 patients to whom NLD irrigation and probing were attempted for CNLDO was 23 months. CNLDO affected a total of 70 eyes. All patients were reviewed for best-corrected visual acuity, refractive errors, and strabismus at a median age of 70.5 months (range 31-95 months). Amblyopia or amblyopia risk factors were identified in 14 patients (27.5%). One child (7.15%) had only strabismus, six children (42.8%) had only amblyogenic refractive errors, two (14.3%) had a combination of two, one child (7.15%) had a family history for amblyopia, but four children (28.6%) had no amblyopia risk factors but had amblyopia.Conclusion:Amblyogenic risk factors are found higher in patients with CNLDO and patients undergoing NLD irrigation and probing in comparison to normal population. Therefore, we recommend these children to routinely undergo cycloplegic refractions and full ophthalmic examinations.