Preliminary findings suggesting cyclic changes in visual contrast sensitivity during the menstrual cycle

Area of Science:

• Ophthalmology
• Neuroscience
• Human Physiology

Background:

• The menstrual cycle involves hormonal fluctuations that can influence various physiological processes.
• Previous research suggests potential links between hormonal changes and sensory perception, but visual system sensitivity during the menstrual cycle requires further investigation.

Purpose of the Study:

• To investigate whether visual contrast sensitivity changes across the menstrual cycle in women.
• To compare visual performance patterns between women with normal menstrual cycles and noncycling controls.

Main Methods:

• Visual contrast thresholds for stationary and moving gratings (2, 4, 16 cyc/deg) were measured over 32 days.
• Participants included two women with normal menstrual cycles and two noncycling controls.
• Time-series data were analyzed using Fourier analysis to examine amplitude spectra.

Main Results:

• Amplitude spectra differed significantly between cycling women and controls.
• Cycling women exhibited distinct peaks in their spectra, suggesting cyclical variations in visual sensitivity.
• These cyclical changes were most prominent for 4 cyc/deg gratings, aligning with the peak of the normal contrast sensitivity function.

Conclusions:

• Visual contrast sensitivity exhibits cyclical variations that correlate with the menstrual cycle.
• The menstrual cycle influences visual perception, particularly at spatial frequencies near the peak of the contrast sensitivity function.
• These findings highlight a potential interaction between reproductive hormones and the visual system.