What is non-24-hour sleep-wake disorder? It is a condition that impacts the natural body clock, thus affecting sleep, and can be triggered by a lack of or no light perception. Tina Snow got in touch after having suffered with this condition for most of her life and she struggled to get the treatment she needed. We have brought Tina together with a world expert in this condition to give information on how the condition works and how it can be treated effectively. We also hear from Tina's GP, who recently sought a individual prescription for melatonin (a natural hormone that regulates sleep) and we hear Kaukub Asia's experience, who also has issues with her circadian rhythm due to her visual impairment.

Presenter: Peter White
Producer: Beth Hemmings
Production Coordinator: Liz Poole
Website image description: Peter White sits smiling in the centre of the image and he is wearing a dark green jumper. Above Peter's head is the BBC logo (three separate white squares house each of the three letters). Bottom centre and overlaying the image are the words "In Touch" and the Radio 4 logo (the word Radio in a bold white font, with the number 4 inside a white circle). The background is a bright mid-blue with two rectangles angled diagonally to the right. Both are behind Peter, one is a darker blue and the other is a lighter blue. Show less