We hope as many women as possible will participate in this study but not all women will be suitable. Please read the sections below to make sure that the study is right for you.
You may be able to participate if
You are over 18yrs old
Have regular menstrual cycles that are within 25-35 days. By regular, we mean that your periods do not vary by more than 9 days in different cycles.
Please do not participate if any of the following apply to you:
You are pregnant or breast feeding
You are taking a progestogen contraceptive pill (Micronor, Noriday, Norgeston, Cerazette, Aizea, Cerelle, Feanolla)
You have a history of menorrhagia (heavy menstrual bleeding)
You are menopausal
You have diabetes
You have any mucopolysaccharide diseases
You are taking any medications which are known to affect vision
You have a drug or alcohol addiction
You are unable to provide informed consent
You have any eye diseases which are known to affect vision. This does not include short-sightedness, long-sightedness, and astigmatism and it is fine to participate in the research if you have these conditions and wear glasses or contact lenses.