You may have heard that you 'shouldn't use screens late in the evening' and maybe even that 'it's good for you to get exposure to sunshine as soon as possible after waking'. For the majority of people, these are generally beneficial heuristics. They are also the extent of most people's knowledge about how light affects their wellbeing.

The multiple mechanisms through which light affects our physiology make it hard to provide generalisable guidance. Among other things, the time of day, your genetics, your age, your mood and the brightness, frequency and duration of exposure to light all interrelate in determining how it affects us.

This document will explain some of the basic mechanisms through which light affects our physiology, with the goal of providing a framework to enable you to make informed decisions around your light exposure. After reading this, at any time on any given day, you should [...]

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Outline:

(01:09) Addressing SAD

(02:53) The Circadian Rhythm

(03:43) Setting Your Clock

(04:49) Living Out of Sync with Your Circadian Rhythm

(05:30) Circadian Light: Frequency, Brightness, Timing

(08:49) Controlling Your Circadian Rhythm for Personal Gain

(08:54) So You Want to Become a Morning Person?

(10:44) What if I Already Am a Morning Person?

(11:22) Mitigating Jet Lag

(12:36) Making it Always Summer

(14:11) Other Times You May Want to Control Your Circadian Rhythm

(15:12) The Immediate Effects of Light on Mood and Cognition

(15:32) Bright Light and Alertness

(16:22) The Calming Effects of Warm Light

(17:05) Negotiating Light

(18:57) Conclusion

The original text contained 36 footnotes which were omitted from this narration.

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First published:

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Narrated by TYPE III AUDIO.

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