Why light matters at bedtime
If you want to drift off easily and get a good amount of uninterrupted, high-quality sleep, it’s important to think about light. We all know light and sleep don’t mix very well, but understanding the science behind why, can help us to get better-quality shut eye and wake up feeling ready to face the day.
Our eyes’ response
We are extremely sensitive to light and dark, mainly due to cells in our eyes that detect the rise and fall of the sun and instruct our brains when to sleep and be awake. To get good-quality sleep, we have to respect this sensitivity and try to stay in tune with the natural light cycles of day and night as much as possible.
As the sun rises, the light stimulates the release of cortisol – the hormone responsible for waking us up and energising us for the day ahead. When the sun sets and it gets dark, our internal body clock triggers the release of the sleep-promoting hormone melatonin, to prepare us for nodding off.
Phones, laptops, TVs, e-readers and any other device with a bright screen emits blue light, which has the same wavelength as sunlight. As a result, looking at screens like these in the last hour before going to sleep or during the night makes our brains think it’s time to wake up.