Bedtime in a household with kids offers a unique set of challenges. For homes with small children, it might be tough getting that fussy baby or toddler off to bed. And for those with older kids, the difficulty may be getting them to unplug and shut down their devices.

With smartphones, tablets, and gaming systems seemingly just about everywhere now, it is not uncommon for kids to spend their time absorbed in a screen during downtime in the evening hours. While earlier generations may have watched television, our current generation of kids is turning to the Internet, mobile devices, and sites like YouTube for a daily dose of entertainment.

Putting aside concerns about keeping tabs on what they are watching and seeing online (an entirely separate issue), there is also a physical consideration to keep in mind. And that is the blue light emitting from these devices, which can possibly interfere with a child’s ability to sleep well and soundly through the night. Sleep experts say that’s because while LED backlight technology helps screens offer more brightness and clarity, it also also emits very strong artificial blue-light waves, which can throw off the body’s internal sleep clock.

“Artificial blue light can negatively impact the circadian rhythm,” said Teresa Stewart, a sleep consultant and child development specialist based in Norwood. “It can suppress the production of the hormone melatonin, which we need to release in order to fall asleep; and it can start to shift the circadian rhythm later; both of these mean it's harder for people to fall asleep and stay asleep. Studies indicate that exposure to artificial blue light for longer than two hours can impact vision, [and cause] eyestrain, blurriness, and headaches.”

“There is supported scientific evidence that the blue light band of visible light generates increased brain activity that can degrade sleep quality and REM cycles,” said Clayton Ostler of Net Nanny, a maker of parental-controls software for computers and mobile devices. “Blue light causes maximum death in retinal cells when compared to other visible light bands, and it can cause long-term vision problems as it increases the likelihood of age-related macular degeneration.”

Mindful of this, technology manufacturers are now responding with what they hope will be a solution to the sleep-blue light connection. Apple, for example, now has a feature available in iPhones and iPads called Night Shift, which it touts as a way of modifying the computer’s display so less blue light is present in the evening. The feature, if enabled, will automatically take effect when the sun goes down, making the phone look “warmer” as the screen displays more of the yellow-orange end of the spectrum. (It can be turned on via General > Display & Brightness > Night Shift.) Stewart said advances like these are a start, but not a substitute for simply unplugging.

“It still doesn't mean that people should be on their devices close to bedtime,” she noted. “Any light exposure tells the body to be awake. So although I think this is a good offering for those who can't put their devices down due to work or other commitments, I would still like to get the bigger-picture message out there: Light reinforces wake-ups and can negatively impact a person's ability to fall asleep or stay asleep.”

Of course, putting limits into place in the home, and stopping device use, is often easier said than done, Stewart added.

“As a mom and a self-employed sleep consultant, I admit I struggle with this, too,” she said. “Technology is so great for many reasons and can be helpful, but it needs to have boundaries. I would encourage families to turn off the cell phones and other handheld devices starting at dinnertime. Preferably, we could keep them off until the next morning, but realistically that might not work for many families. So can they be off until your children are asleep? If that's not feasible, then what about for one hour every night, there are no devices used.”

Melissa Carriveau, a Shrewsbury mother of three, has her children turn off devices at a certain time before heading off to bed each night.

“All devices in our bedroom 30 minutes before lights out,” Carriveau said. “Typically this means they read until falling asleep, which I like. As a principal in one school once told [me]: ‘There's nothing good that can come out of a 12-year-old looking at his device in the middle of the night.’ I liked that advice.”

“We can’t reasonably say to never use a mobile device or avoid electronic screens, but we can set limitations,” Ostler noted. “Parents can set family rules regarding daily screen time allowances and set rules around times when devices should be shut off or unavailable.”

Ostler offered the following tips for minimizing device use and the struggle to unplug in the evening:

    Have a time when all devices should be shut off.
     Never let your kids take a device to bed or put one in an area they could see while in bed.
     Create maximum screen time rules for your household.
     Don’t let kids go to sleep while watching a TV, tablet, or any kind of screen.
     Consider a central location where devices are stored at night to help kids avoid temptation.