The blue light emitted by your cell phone screen restrains the production of melatonin, the hormone that controls your sleep-wake cycle (aka circadian rhythm). This makes it even more difficult to fall asleep and wake up the next day. … Studies also show that exposure to blue light can cause damage to your retinas.
When you call a dead phone does it ring?
Answer: A: With a dead battery it should not ring but it should go to voicemail directly.