A man's eyesight deteriorated after the Southern District Health Board ophthalmology service failed to provide timely check ups.
Health and Disability Commissioner Anthony Hill released a report into the treatment of a man with complex glaucoma.
The man, referred to as Mr A, had regular appointments for glaucoma since 2012, including an annual visual field test.
In 2015, Mr A was seen by a locum who delayed his upcoming visual field test by five months until after cataract surgery.
The appointment was then delayed another three months, by which time the man's eyesight was so bad he could no longer drive and needed surgery.
Mr Hill asked the DHB to apologise to Mr A, and said recommendations from a case earlier this year, including building capacity, were also applicable in this case.