Many adults (58 percent) use a tablet, smartphone or computer in the hour before they go to bed on a daily or almost-daily basis. Using these devices shortly before going to bed is associated with sleeping less or poor quality of sleep. That is the conclusion of a study by the RIVM commissioned by the Netherlands Consumer Product and Food Safety Authority (NVWA) and conducted in cooperation with Utrecht University’s Institute for Risk Assessment Sciences (IRAS).
Light is an important factor in setting our biological clock. Most recently developed sources of light, including tablets, mobile telephones, LED televisions and light bulbs, emit more blue light than traditional sources of light. Poor sleep may be caused by the blue light emitted by these screens, but this type of research cannot prove a causal relationship. The researchers point out that people may be more alert when using these types of screens, which in turn makes it more difficult for them to fall asleep. Or perhaps they use the tablet or smartphone because they have difficulty falling asleep. It is currently unknown whether the blue light may be the cause of other health effects over the long term.
Watching TV before sleeping
This study examined the subjects’ television habits. A large majority of the respondents watches television in the hour before going to bed every night, or several evenings per week. The study did not find a correlation between watching television before going to sleep and changes in sleep patterns.
This study was the first to survey a relatively large number of adults: almost 16,000. As it seems that many people look at screens shortly before going to bed, the researchers recommend that additional research be conducted into the relationship between sleep and possible long-term health effects.