IF you crul up under the blanket with an e- book for a bedtime read then you are not only damaging your sleep and health but also interrupt your DNA . US doctors have warned that . A team from.Harvard Medical School compared reading paper books and light emitting e-readers before sleep . They found it tool longer to nod off with a back lit ereader which led to poorer quality sleep and being more tired the next morning not only that these radiations also makes our DNA manipulation which results in damaging DNA. Our bodies are kept in tune with the rhythm of day and night by an internal body clock which uses light to tell the time. But blue light , the wavelength common in smart phones, tablets and LED lighting is able to disrupt the body clock . Blue light in the evening can slow or prevent the production of the sleep hormone melatonin. It results in hormonal changes also. DNA aminoacids can change their positions by radiations . E- books radiations do this job slowly . So try not to use E - books in night for making yourself healthy...