Daily Calm: Dark evenings, light and your mood

Daily Calm, from Central London Hypnotherapy

The clocks have gone back, the light is gone before the commute home, and plenty of people feel their mood drop with it. A review posted this month, Ocular Phototherapy and Mental Health: What Vision Scientists and Clinicians Need to Know, looks at how bright light acts on mood through the eyes, and why the number printed on a light box can be misleading.

What the study found

Mood responds mainly to special light-sensing cells in the retina that contain a pigment called melanopsin. They work alongside the rods and cones we use to see. Blue light, at roughly 446 to 477 nanometres, most strongly suppresses the sleep hormone melatonin.

In trials on seasonal depression, narrow-band blue light did better than dim red light, but no better than broad white light. The authors also worked out that two lamps both sold as 10,000 lux can deliver very different doses to those cells, from about 4,100 to 10,000 equivalent units, depending on their colour mix. Age matters too: a 75-year-old eye receives roughly half the effective dose of a 25-year-old one.

This is a narrative review posted as a preprint, built on published trials and standard calculations rather than a new trial. We read the abstract only, as the full text is not open.

Where the news coverage and the science line up

A Firstpost explainer this week makes the broad point that seasonal low mood usually starts as winter approaches and that strong light helps many of the people affected. The review agrees on direction but adds the fine print. Whereas the news story treats light as one simple fix, the review argues that the dose reaching your eye depends on colour, how far away the lamp sits, pupil size and age. It also warns that piling on extra blue light for an older eye raises its own safety worries.

What this looks like in winter

Office lighting is far dimmer than daylight, even on a grey day. Many Londoners now go from a dark morning to a desk and back into darkness. The review suggests the eye notices that difference more than we do.

What it means for you

• Get outside in the first hours of daylight, even for fifteen minutes on a lunch walk.
• If you try a light box, place it as the instructions say and use it at a regular time each morning.
• Protect the evening: dimmer, warmer light after dark helps your body tell night from day.

Where hypnotherapy fits

Short days often bring restless nights. Hypnotherapy can help you relax and may aid sleep. A 2015 review of trials found that people fell asleep faster after hypnosis than people on a waiting list, though not faster than people given a sham treatment, and a 2018 review of 24 studies found that 58% reported positive results. Sessions focus on winding down, so light by day and calm by night work together. The page on hypnotherapy for insomnia in London explains more.

Tim Dunton brings more than twenty years of practice, GHR membership and NLP training with Bandler and Grinder to every session. For the wider picture of winter pressure, see hypnotherapy for stress in London.

Book a free consultation. A relaxed 15 to 30 minute chat in London or by video call: book your free chat here or ring Tim on 07975 653893.

The research

1. Ocular Phototherapy and Mental Health: What Vision Scientists and Clinicians Need to Know, preprint, November 2026. https://doi.org/10.31234/osf.io/x5eca_v2

2. Firstpost, "A change in seasons can cause depression. How light exposure can help", November 2026. https://www.firstpost.com/explainers/a-change-in-seasons-can-cause-depression-how-light-exposure-can-help-14058119.html

3. Lam TH et al. Hypnotherapy for insomnia, systematic review and meta-analysis, Complementary Therapies in Medicine, 2015. https://pubmed.ncbi.nlm.nih.gov/26365453/

4. Chamine I, Atchley R, Oken BS. Hypnosis intervention effects on sleep outcomes, Journal of Clinical Sleep Medicine, 2018. https://pubmed.ncbi.nlm.nih.gov/29198290/

Tags: sleep · stress · winter · research

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