VA and stereo changes with increasing Bangerter filters
Reviewed by Fiona Rowe

This study investigated the effect of monocular blur induced by Bangerter filters (BF) on both monocular and binocular visual acuity (VA) and stereoacuity in normal visual systems. Subjects included 24 healthy student volunteers aged 20.33 ±1.79 years; 22 female. One was excluded from analysis. BFs were all placed before the right eye. There was a significant reduction in right monocular visual acuity as filter strength increased and with the smallest significant difference between the 0.6 and 0.4 filters. Except for the 0.4 filter, there was a graded reduction in visual acuity as filters changed. Filters did not reduce binocular visual acuity below normal levels. Mean stereoacuity reduced significantly with the main difference between 0.1, 0.2 and 0.4 filters but not between 0.6 and 0.4. Overall, there was a significant negative correlation between monocular visual acuity and stereoacuity degraded by BFs but with significant variability between subjects. The authors discuss the potential for use of BFs in the management of amblyopia and intractable diplopia. Further research is needed to investigate the association between degraded visual acuity and lower order binocular functions.

The effect of induced monocular blur by Bangerter filters on measures of visual acuity and stereoacuity.
Williamson I, Keating P, Bjerre A.
STRABISMUS
2021;29(2):74-80.