The Effects Of Bioptic Telescopes On Contrast Sensitivity

Background: Low vision devices are becoming more widely used in America. We expect
this trend to continue as a large portion of the population ages and more people fall victim to sight-threatening diseases. Currently, bioptic telescopes provide visually impaired individuals with greater independence by enhancing their distance visual acuity. However, there is a lack of information available about how bioptic telescopes affect contrast sensitivity for the purpose of mobility and detail tasks. It is the intention of this project to address the issue of how bioptic telescopes influence contrast sensitivity.
Methods: This study examines the effects ofbioptic telescopes on contrast sensitivity by
testing subjects' contrast sensitivity in each eye with the best corrected acuity by means of
a Bailey-Lovie Acuity Chart at distance with and without a bioptic telescope. Our test
population is normally sighted, near normally sighted, visually impaired, and legally blind subjects as defined by the American Optometric Association. Results: All groups demonstrated an average improvement in contrast sensitivity with the telescope. All groups except for the legally blind showed more improvement with the telescope while viewing the low contrast chart compared to viewing the high contrast chart.
Conclusions: All of the data suggest that there is no adverse effect of the Galilean telescope when used for driving purposes. The contrast sensitivity of the driver seems to actually improve through the bioptic telescope. The results of this research support the continued use ofbioptic telescopes by visually impaired drivers. More research needs to be completed to gain a better understanding of how telescopes affect contrast sensitivity and other factors involved in driving.