Background Home visual acuity tests could ease pressure on ophthalmic services by facilitating remote review of a variety of patients. Home tests may have further utility in giving service users frequent updates of vision outcomes during therapy, identifying vision problems in an asymptomatic population, and engaging stakeholders in therapy. The accuracy of home vision tests for children when completed without supervision from a professional is unknown. Methods Children attending outpatient clinics had their visual acuity measured 3 times in a randomised order at the same appointment. Once by a registered orthoptist as per standard clinical protocols, once by an orthoptist using a tablet-based visual acuity test (iSight Pro, Kay Pictures), and once by an unsupervised parent or carer using the tablet-based test. Results 42 children were recruited to the study. The mean age was 5.6 years (range 3.3 to 9.3 years). Median measurements (interquartile range) for clinical standard, orthoptic-led and parent/carer-led iSight visual acuity measurements were 0.155 (0.18), 0.180 (0.26), and 0.300 (0.33) respectively. The iSight app in the hands of parents/carers was significantly different from the standard of care measurements (P=0.009). In the hands of orthoptists, there was no significant difference between the iSight app and standard of care (P=0.551), nor was there significant difference between parents/carers using the app and orthoptists using the app (P=0.133). Conclusion This technique of unsupervised home visual acuity measures for children is not comparable to clinical measures and is unlikely to be valuable to clinical decision making and screening. Future work should focus on improving the technique through, for example, gamification of vision tests.

Background Home visual acuity tests could ease pressure on ophthalmic services by facilitating remote review of patients. Home tests may have further utility in giving service users frequent updates of vision outcomes during therapy, identifying vision problems in an asymptomatic population, and engaging stakeholders in therapy. Methods Children attending outpatient clinics had visual acuity measured 3 times at the same appointment: Once by a registered orthoptist per clinical protocols, once by an orthoptist using a tablet-based visual acuity test (iSight Test Pro, Kay Pictures), and once by an unsupervised parent/carer using the tablet-based test. Results In total, 42 children were recruited to the study. The mean age was 5.6 years (range 3.3 to 9.3 years). Median and interquartile ranges (IQR) for clinical standard, orthoptic-led and parent/carer-led iSight Test Pro visual acuity measurements were 0.155 (0.18 IQR), 0.180 (0.26 IQR), and 0.300 (0.33 IQR) logMAR respectively. The iSight Test Pro in the hands of parents/carers was significantly different from the standard of care measurements (P = 0.008). In the hands of orthoptists. There was no significant difference between orthoptists using the iSight Test Pro and standard of care (P = 0.289), nor between orthoptist iSight Test Pro and parents/carer iSight Test Pro measurements (P = 0.108). Conclusion This technique of unsupervised visual acuity measures for children is not comparable to clinical measures and is unlikely to be valuable to clinical decision making. Future work should focus on improving the accuracy of the test through better training, equipment/software or supervision/support.