Related Experiment Video
Updated: May 13, 2026

An Automated Method for Assessing Visual Acuity in Infants and Toddlers Using an Eye-Tracking System
Published on: March 17, 2023
Accuracy of visual acuity testing in New Zealand primary health care
Nishanthan Ramachandran1, Gordon Sanderson, Tui H Bevin
1University of Otago Dunedin School of Medicine, PO Box 913, Dunedin 9054, New Zealand.
Aim:
To determine if visual acuity is tested reliably in primary health care in New Zealand.
Methods:
Fifteen to 26 'eyes' from seven participants were tested in the Eye Department of Dunedin Hospital under standardised conditions; and across 17 centres in nine general practices and the Emergency Department of Dunedin Hospital for comparison. Variables including lighting and distance were measured; chart type and centre conditions were recorded.
Results:
Eleven centres (65%) produced visual acuity scores that were inconsistent with the Eye Department, where 10 (59%) of them produced worse visual acuity scores and one centre (6%) produced better visual acuity score. Ten centres (59%) did not meet New Zealand Transport Agency standards of adequate illumination of greater than 500 lux. Ten centres (59%) failed to have their charts at the specified distance.
Conclusion:
There were inconsistencies in visual acuity testing in primary health care in Dunedin, New Zealand which may be related to the overall poor compliance with lighting and distance standards. These factors are potentially easily modifiable and their change should lead to improvements in visual acuity measurements.

