Myopia-Night Blindness Clinical Trial
Official title:
Evaluation of a Night Spectacle Correction Concerning an Improvement of Mesopic Vision Quality
Reduced quality of vision and glare in twilight or night are frequently mentioned complaints
within the optometric examination. A reason for these problems could be a myopic refractive
shift in dark light conditions, commonly known as night myopia or twilight myopia.
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.
After obtaining informed consent, aberrometry was performed in a darkened room (0.1 lux).
Subjective photopic refraction and visual acuity were measured before light was turned off
and mesopic refraction was obtained after a dark adaptation period of five minutes. Finally,
frames and lenses were fitted by a centration system. Lens grinding was executed centralized
by a grinding workshop. In the course of this study, subjects were randomly assigned to wear
two glasses double-masked in turn. One with photopic subjective refraction data and another
with mesopic subjective refraction data. Both were worn for 14 ± 2 days each.
Follow Up 1:
After two weeks, participants were asked for their subjective experiences with the first
correction by a visual analogue scale questionnaire. After the evaluation, glasses were
changed.
Follow Up 2:
Two weeks later, subjective experiences were evaluated again. After visual analogue scale
questionnaire, subjects were asked to compare the two glasses concerning quality of mesopic
vision and subjective safety level during night driving.
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