Background The red reflex test (RRT) is widely used as a screening tool to detect congenital cataract. This study aims to determine the incidence of congenital cataract in Northern Ireland and to evaluate the success of the RRT screening programme. Methods Retrospective review of consecutive abnormal red reflex referrals in 2017 and 2018 inclusive. We collected data on the source and timing of referral, diagnostic outcome, visually significant cataract, and surgical intervention. Additionally, data was collected on all cases of confirmed congenital cataract diagnosed in the Regional Paediatric Ophthalmology Service within the same time period. Results In the study period, 179 children with suspected red reflex abnormalities were referred. In the same period, thirteen patients were diagnosed with visually significant congenital cataract under one year. Eight (62%) were female and seven (54%) affected both eyes. Only 46% were detected through the screening programme. Three children were above one year of age at the time of diagnosis with sub-optimal outcomes. Six patients were diagnosed with non-visually significant congenital cataract and one juvenile onset were not included. Eight infants diagnosed with lens opacities required surgical intervention. Incidence of visually significant congenital cataract in Northern Ireland was calculated at 2.8 per ten thousand live births per year. Conclusions Northern Ireland has a similar incidence of congenital cataract compared to the remainder of the UK. This study highlights that red reflex screening requires further refinement, which can be augmented by pupillary dilatation, to ensure timely diagnosis and improve visual outcomes. ​