Abstract
Purpose :
Night myopia is discussed to be a possible reason of vision problems in dark light conditions. The aim of this study was to investigate whether quality of vision in twilight or night could be improved by a spectacle correction optimized for mesopic light conditions. Moreover, objective refraction in large pupils measured by aberrometry was compared to subjective mesopic refraction.
Methods :
Data of 100 subjects aged from 18 to 40 were analyzed in this prospective, randomized, double-masked, multicentric cross-over study. For aberrometry, devices of the Visionix VX 120 family were used. Study participants’ subjective refraction was obtained under both, photopic and mesopic light conditions. In the course of this trial, a conventional spectacle correction for photopic light conditions and a sphero-cylindrical optimized mesopic spectacle correction were tested for two weeks each.
Results :
Compared to photopic light conditions visual acuity was found to be physiologically reduced in mesopic conditions by 0.2 logMAR units. Subjective spherical equivalent change was -0.30 ± 0.2 D in mesopic light conditions (p<0.001). Components of Astigmatism did not significantly change. With the mesopic correction a median visual acuity improvement of 0.1 logMAR units could be achieved (p<0.001). Subjective comfort of vision and sharpness could be improved while subjective glare could be reduced by wearing the mesopic correction (p<0.01). 75 % of the subjects reported an improved quality of vision at night when wearing the night spectacle correction. However, changes of pupil size-depended objective refraction values were not comparable to changes in luminance-dependent subjective refraction data.
Conclusions :
Wearing spectacles fitted with optimized refraction values for mesopic conditions results in an improvement of mesopic vision quality. Particularly for individuals with night vision complaints, a mesopic subjective refraction should be performed within an optometric examination.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.