Some of the non-image forming effects of light exposure depend on the colour of light in combination with timing of exposure. Some colours and intensities that are beneficial at one time of day may be detrimental at other times of day.
Exposure to light in the morning, especially light with a more bluish colour, is needed in most people to properly wake up, become energetic and to keep the sleep-wake cycle in synch with the natural 24-hour cycle. This is not the case in morning types; they should try to avoid too high and bluish light in the early morning.
Exposure to light during daytime is beneficial to improve low levels of energy and mood if needed. The more bluish the white light is, the lower the intensity that is needed to reach a response. Too high levels of blue light and definitely exposure of the eyes to UV light should always be avoided to protect the eyes.
Exposure to bright light, and definitely bluish light, in the evening is in most cases not recommended. Most people already tend to go to bed too late and exposure to bright light in the evening even increases levels of alertness. This in turn increases the risk of going to bed later and shorten sleep. Only people who suffer from high levels of sleepiness in the evening and waking up early may be helped by exposure to bright light in the evening.
Exposure to light, and especially bluish light, at night should be avoided as much as possible. It may increase energy levels and reduce sleep, but it may also induce undesirable large phase shifts of the biological clock, and affect physiological parameters such as body temperature, heart rate and melatonin concentration. This may induce health risks on the long term.
Too high levels of blue light and definitely exposure of the eyes to UV light should always be avoided to protect the eyes. EnergyUp devices are designed in such a way that they do not represent any risk to normal healthy eyes according to the international photobiological safety standards. This is so due to both even brightness of the light screen without hot spots, and the color selection avoiding the most hazardous short wavelength blue, and total absence of ultraviolet light.