The data is for the sixth prospective year of the National Cataract Audit corresponding to the 2021 NHS year (01/04/2021 to 31/03/2022). The data was collected as part of routine clinical care on electronic medical record systems in 159 participating centres. The three metrics used in the national cataract audit are case ascertainment and adjusted rates for posterior capsular rupture and visual acuity loss. The denominator for case ascertainment was the number of cataract operations reported to NHS digital or Digital Health and Care Wales (DHCW) performed using phacoemulsification. Operative data is more consistent than postoperative data as not all centres use the electronic medical record systems in all areas of their hospital eye service. Postoperative results do not include operations performed in the last 2 months of the audit year or for centres with <50 eligible operations in the postoperative time period. Visual acuity estimates are only produced for centres with at least 50 eligible operations with the relevant visual acuity measurement. Comprehensive information regarding the eligibility criteria used in the National Cataract Audit can be found on the audit website (www.nodaudit.org.uk). Results are provided for contributing NHS Trusts, Welsh Health Boards, Independent Sector Treatment Centres (ISTC), one private sector provider centre and one centre from Guernsey. The results for Bradford Teaching Hospitals NHS Foundation Trust include patients from Airedale Hospital NHS Foundation Trust as cataract surgery for Airedale patients is performed in Bradford Teaching Hospitals NHS Foundation Trust sites. Results for Moorfields Eye Hospital NHS Foundation Trust include data for patients treated in Bedford Hospital from the Bedfordshire Hospitals NHS Foundation Trust and data for patients treated in the Croydon Health Services NHS Trust.