As in 2011, Census 2021 asked usual residents to report if they had a long-term health condition or illness, lasting or expected to last 12 months or more.
Adroddiad offthalmolegydd neu ffurflen CV1/BD8 yn cadarnhau bod y person “â nam difrifol ar ei olwg (dall)” neu gofrestriad gydag awdurdod lleol fel unigolyn â nam ar ei olwg