Getting to sleep isn’t always as simple as turning off the lights and going to bed. Those lights might go off with the flick of the switch, but the effects of constant light exposure can linger, especially when it’s light from devices such as computers, iPads, and e-readers. Light from these and other electronics may not look blue, but they are heavy in blue wavelengths – the same type of blue light your body relies on to know day from night. When you spend too much time staring at a device, especially in the evening and at night, your body thinks it’s still daytime and production of the “sleep hormone,” melatonin, is delayed. The result: a lot of tossing and turning. If you’re having trouble sleeping, try minimizing light exposure in the evening, especially exposure to electronic lights. If you have to work on a computer at night, consider computer glasses, which block blue wavelengths. And for your bedtime reading, choose an old-fashioned book over an e-reader.