Purpose: Consistent variations in reports of visual discomfort during the female menstrual cycle are found when virtual reality headsets are used to display moving images. Because little is known about the influence of this cycle on susceptibility to visual discomfort in other situations, we performed a laboratory study using an intensive visual task.
Methods: Twelve female participants, with normal-length menstrual cycles, completed the study. This required them to play a computer game for 30 minutes while viewing the screen through -2.00-D lenses. Questionnaires were used to record symptom changes; visual acuity and near points of accommodation (NPA) and convergence (NPC) were also recorded both before and after the game. The participants performed this task on designated days (5, 12, 19, and 26) of their menstrual cycle chosen because they fall in line with peaks and troughs of ovarian hormone levels. Cycle phase was confirmed by the measurement of salivary estradiol and progesterone levels.
Results: The task performed produced clear changes in all metrics examined. Visual discomfort first increased, on average, after 6 minutes; VA declined on average by 0.02 logarithm of the minimum angle of resolution and NPC and NPA both receded by just over 1 cm. However, none of these changes differed significantly at any stage of the menstrual cycle.
Conclusions: We conclude that visual discomfort, generated by providing increased accommodative demand while viewing a visual display unit, does not vary significantly during the menstrual cycle.