Impact of Sex and Age on Non-visual Light Input That Affects Sleep and Circadian Rhythms

Summary

The goal of this clinical trial is to learn how the pupil responds to different light stimuli and how that relates to sleep and daily rhythms in healthy people of different ages. The main questions it aims to answer are: * Does the eye's pupil response to light stimuli differ by the sex and age of the participant? * Is the eye's pupil response to light stimuli related to each participant's sleep timing, their body clock timing, and their hormone responses to light. Participants will have a special eye exam and complete questionnaires before starting the study to see if they can participate. If they can participate, they will wear a special watch that monitors their activity and light levels for one week. Then they will live in a research room at the Mass General Hospital for 3 days/2 nights during which we will test their pupil response to light, their body clock timing, and their hormone responses to light.

Eligibility

Age range

18–85 years

Sex

All

Healthy volunteers

Yes

Interventions

• Device
  Pupillometry

  Pupillometer measurement of pupil size in response to different light stimuli

• Device
  Light box exposure

  Using a light box to produce different wavelengths and intensities of light. Exposure to red light on Night 1 and blue/green light on Night 2 to determine circadian timing and suppression of hormone (melatonin)

Location