Joined in 2023 
82 
63 About this deal
Blue light is essential for regulating the circadian rhythm, because it stimulates melanopsin receptors in the eye. [20] This suppresses daytime melatonin, enabling wakefulness. Working in blue-free light (aka yellow light) for long periods of time disrupts circadian patterns because there is no melatonin suppression during the day, and reduced melatonin rebound at night.
Blue light from sunlight is very important in regulating circadian rhythm — our natural wakefulness and sleep cycle. Exposure to blue light from the sun during daytime hours helps maintain a healthy circadian rhythm. Blue light filters and protective eyewearUV rays have higher energy than visible light rays (including blue light), which makes them capable of producing changes in the skin that create a suntan. The bulbs in tanning booths emit a controlled amount of UV radiation specifically for this reason.
Light-emitting-diode induced retinal damage and its wavelength dependency in vivo" (PDF). International Journal of Ophthalmology, Vol. 10, No. 2. Feb 18, 2017. Lissak G. Adverse Physiological and Psychological Effects of Screen Time on Children and Adolescents: Literature Review and Case Study. Environmental Research. July 2018.Blue light does affect the body’s circadian rhythm, our natural wake and sleep cycle. During the day, blue light wakes us up and stimulates us. But too much blue light exposure late at night from your phone, tablet or computer can make it harder to get to sleep. Jagannath, A., Taylor, L., Wakaf, Z., Vasudevan, S. R., & Foster, R. G. (2017). The genetics of circadian rhythms, sleep and health. Human molecular genetics, 26(R2), R128–R138.
While light of any kind can suppress the secretion of melatonin, blue light at night does so more powerfully. Harvard researchers and their colleagues conducted an experiment comparing the effects of 6.5 hours of exposure to blue light to exposure to green light of comparable brightness. The blue light suppressed melatonin for about twice as long as the green light and shifted circadian rhythms by twice as much (3 hours vs. 1.5 hours). Downie LE, et al. (2019). Analysis of a systematic review about blue light–filtering intraocular lenses for retinal protection. Not all colors of light have the same effect. Blue wavelengths—which are beneficial during daylight hours because they boost attention, reaction times, and mood—seem to be the most disruptive at night. And the proliferation of electronics with screens, as well as energy-efficient lighting, is increasing our exposure to blue wavelengths, especially after sundown. Light and sleep Without getting into complicated physics, there's an inverse relationship between the wavelength of a light ray and the amount of energy it contains. Light rays that have short wavelengths have more energy and those with longer wavelengths contain less energy. The issue is fuzzier around eye health, though (more on this further down). Lots of uninterrupted screen time can absolutely irritate your eyes, though the issue may simply be because you’re focusing your attention at a fixed distance for hours on end, and therefore straining your vision. As ever, it’s good advice to take regular breaks from your screen, look out the window (if you have one), and walk about when you can to vary the distance your eyes are focusing on.Sit an arm’s length (about 25 inches) away from the computer screen, and position the screen so you’re looking slightly downward. While current research indicates that blue light from computer screens and handheld devices probably does not pose a serious risk to your eyes, there are some other risks to consider.
The light sources for this therapy emit bright white light that contains a significant amount of blue-turquoise light. Chang A-M, et al. (2015). Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. The result is that you lose the ability to see the center of your field of vision. You may still be able to see things on the periphery. But details and objects in the center of your sight lines may become blurry and, over time, more difficult to see. The circadian rhythm is a mechanism that regulates sleep patterns. One of the primary factors affecting the circadian rhythm is the excitation of melanopsin, a light sensitive protein that absorbs maximally at 480nm, but has at least 10% efficiency in the range of 450-540nm. [16] The periodic (daily) exposure to sunlight generally tunes the circadian rhythm to a 24-hour cycle. However, exposure to light sources that excite melanopsin in the retina during nighttime can interfere with the circadian rhythm. Harvard Health Publishing asserts that exposure to blue light at night has a strong negative effect on sleep. [17] The aforementioned ANSES report "highlights [the] disruptive effects to biological rhythms and sleep, linked to exposure to even very low levels of blue light in the evening or at night, particularly via screens". [18] A 2016 press release by the American Medical Association concludes that there are negative effects on the circadian rhythm from the unrestrained use of LED street lighting and white LED lamps have 5 times greater impact on circadian sleep rhythms than conventional street lamps. [19] However, they also indicate that street lamp brightness is more strongly correlated to sleep outcomes. The Vision Council Shines Light on Protecting Sight — and Health — in a Multi-Screen Era. The Vision Council. January 7, 2019.Bullough, John D.; Bierman, Andrew; Rea, Mark S. (3 April 2019). "Evaluating the blue-light hazard from solid state lighting". International Journal of Occupational Safety and Ergonomics. 25 (2): 311–320. doi: 10.1080/10803548.2017.1375172. PMID 28876164. S2CID 10490626. All three are new police officers in their probation period with the PSNI, the odds are at least one of them isn’t going to last. The pressure is immense, but if they succumb to it, they won’t survive. Often the rookie officers don’t know the extent of the peril they are in, or who they can trust. What’s it like to have to hide your job from neighbours, friends and even family? How do you distinguish between who needs your help and who wants you dead simply because of the uniform you wear? US. Department of energy. (2013). Solid-State Lighting Technology Fact Sheet (Optical Safety of LEDs). Available at: https://www.lightingglobal.org/wp-content/uploads/bsk-pdf-manager/82_opticalsafety_fact-sheet.pdf
Great Deal 
New Comment