Poor sleep and being chronically under-slept affects concentration, while also reinforcing those stress hormones to compensate, making it a bit of a vicious circle. Improving sleep cannot happen overnight, particularly if it is a chronic problem, but taking measures to improve this will yield results over a period of weeks, rather than days.
One place to start is clearing your bedroom of TVs, computers and other technology. Although any type of light can inhibit sleep, research has shown that light towards the blue end of the spectrum is especially effective at keeping you awake because it stimulates the retina in the eye and inhibits the secretion of melatonin from the pineal gland in the brain.
Computer screens, tablets, smartphones, flat-screen TVs and LED lighting all emit large amounts of blue light, and it is important to avoid these before trying to sleep. Around 80% of people routinely use these devices running up to bedtime, and among 18 to 24-year-olds this figure increases to 91%, according to research carried out by Prof Richard Wiseman.
Amber-tinted glasses can cut out glare, and it is also possible to fit screens with commercially produced blue-light blocking filters. Another solution, of course, is to avoid all electronic devices before bed in order to help avoid insomnia and improve sleep.