Dangers of Exposure to White Light

White light used in homes, offices and outdoors affects people’s biological clock and disrupts sleep patterns due to the high blue light it contains. High and prolonged exposure to white light causes toxic stress on the retina, negatively affecting visual performance.

In the retina, which covers the posterior wall of the eye, there are blue light photoreceptors that communicate directly with the circadian clock in brain. The blue light reaching the retina negatively affects the sleep rhythm by preventing the secretion of the sleep-promoting melatonin hormone.

Prolonged exposure to white light can cause structural and functional damage to the retina. Deterioration in retinal function is directly related to light intensity. It is known that people who are exposed to high levels of white light during the night shift are also at greater risk for breast, prostate and colorectal cancers.

White light can also cause symptoms of fatigue, lack of attention, difficulty concentrating, and depressed mood.

The harmful effects of white light are not limited to humans. Other living things in nature also get their share from it. White light used outdoors can cause animals to sleep less and lead to certain metabolic changes that indicate poor health. High-brightness white light can cause flying animal species to lose their migration routes and habitats.

Since the emission surfaces of LED light sources are highly concentrated points, the visual disturbance can be much greater. In this case, it would be a good solution to use optical materials that will soften and disperse the light. In order to reduce the level of direct radiation to the eye, indirect lighting systems, in which the light is reflected from surfaces such as walls and ceilings, can be used instead of direct lighting.

Prolonged staring at computer, smartphone and television screens as well as lighting sources can cause similar problems. Looking at the phone screen for a long time, especially at late hours, can prolong the transition to sleep and reduce sleep quality. Aware of this effect, display manufacturers are working on hardware that reduces the effect of blue light.

Children are much more sensitive to the negative effects of white light than adults. To protect children, yellow lights should be preferred in children’s rooms and they should be restricted from using electronic devices before going to bed.