response to light? the internal clock? enough sleep?

you guys do realize we've gone for millions of years without alarm clocks, don't you?

there's this thing called the circadian cycle...
djaio Reviewed by djaio on . how do deaf people wake up? im not being offensive here or anything its just if there deaf,they wont be able to hear an alarm,and if they lived alone theres no one to wake them up. any ideas? Rating: 5