A new study* highlights the disruption to sleep patterns which can be caused by blue light emitted from digital devices.

The study, at the University of Houston College of Optometry, had people wearing blue blocking filters before bed. Participants still performed their usual nightly digital routine. Results showed a 58% increase in night-time melatonin levels. Melatonin is the chemical that signals your body its time to sleep. These melatonin levels were higher than would be achieved taking over-the-counter melatonin supplements.

“The most important takeaway is that blue light at night time really does decrease sleep quality. Sleep is very important for the regeneration of many functions in our body,” said Dr. Ostrin, from University of Houston College of Optometry.

The 22 study participants wore sleep monitors 24 hours a day. They reported sleeping better, falling asleep faster, and even increased their sleep duration by 24 minutes a night.

The largest source of blue light is sunlight, but it's also found in most LED-based devices. Blue light boosts alertness and regulates our internal body clock, or circadian rhythm, that tells our bodies when to sleep. This light activates photoreceptors, called intrinsically photosensitive retinal ganglion cells (ipRGCs), which suppresses melatonin.

Dr. Ostrin recommended limiting screen time, applying screen filters, wearing computer glasses that block blue light, or using anti-reflective lenses to offset the effects of artificial light at night time. Some devices have night mode settings that limit blue light exposure.

“By using blue filtering lenses we are decreasing input to the photoreceptors, so we can improve sleep and still continue to use our devices" she said.

Closer to home we are dispensing blue coating on lenses. This coating improves comfort looking at screens. Wearers also find the blue coat is good for driving. Blue light causes light scatter so in daylight conditions blocking this reduces glare. Please contact us if you have any questions about lens coating options.

*Study published in Ophthalmic & Physiological Optics.