Is sleeping different for blind people?

Is sleeping different for blind people?

Yes, sleeping can be different for blind people . . . so one of the things about the biological clock is it's controlled hugely by light. And the biological clock normally runs slowly; dawn light speeds it up every day. If one's blind and there's no information going into the biological clock, then that reset doesn't occur, so their clocks slowly drift during the day. Which means they can be sleeping well during the night to start with, but a day later they'll be going to bed slightly later and waking up slightly later. A fortnight later they could be sleeping well during the day but they can't sleep during the night. A fortnight later they'll be sleeping well during the night again, not during the day, so that reset's not occurring. So a lot of blind people will suffer from insomnia. It's not really insomnia because the biological clock isn't sticking to the right time for them.