The suppression of melatonin by light at night reading that results in circadian disruption has been implicated in sleep disturbances, an increased risk for diabetes and obesity, as well as increased risk for more serious diseases, such as breast cancer, if circadian disruption occurs for many consecutive years, such as in nightshirt workers.) (publishingperspectives.com)
The shape is so useful that we're still comfortably wearing some old ones as nightshirts, since they're so short. (garnethill.com)