Many studies are ongoing to understand the blue light impact on mankind and how harmful it is to our eyes. At the same time, spectacles and software business are booming in the name of protecting eyes against blue light.
So let us discuss how coloured light affects sleep. Computers, and smartphone use have been identified as a source of disturbance because of blue light emitted by their displays. Scientists studied the impact of coloured light on the sleep pattern of mice to learn how different colours act on a body. They found that twilight –dimmer and bluer light than normal daylight produces a physical signal about when to sleep, so using brighter, warmer lights in the day and dimmer lights in evenings could be far better for health.
There was a study based on the effect of light on suppression and phase delay of melatonin rhythm. Lights with different wavelengths were compared for melatonin suppression and phase shifting of the salivary melatonin rhythm. The results were consistent with the involvement of scotopic mechanism in the regulation of the area of sleep, so they concluded blue light could disrupt sleep.
The researchers expected that these experiments disrupt circadian rhythm because of melanopsin photopigment in the eye. The light-sensitive protein is seen in retina, ganglion cells for mammals .Melanopsin maintain circadian rhythm and are sensitive to blue light.
The Manchester group did experimentation by different wavelengths those were used to lights that changed colour without altering brightness. They confirmed that equally bright yellow or bright white light has a stronger influence on our sleep than blue light.
Dr. Tim Brown, a senior lecturer at the school of medical sciences replied that changes in colour may oppose any benefits obtained from reducing the brightness signals detected by melanopsin.
Harvard medical school comments that blue light exposure can lead to the risk of cancers, heart diseases, obesity, etc,. Though sunlight is the major source of blue light but prolonged exposure to electronic screens can damage light-sensitive cells in the retina can cause cataract mainly dryness. So what can we do to prevent is the 20-20 rule from the American optometric association. Take atleast a 20-sec break from your screen every 20 minutes to look at something 20 feet distance, this will break your stare and help you to relax and improve vision.
-Keerthana Joshi
Author
