{"id":838,"date":"2018-05-14T09:00:56","date_gmt":"2018-05-14T13:00:56","guid":{"rendered":"https:\/\/designinglight.com\/?p=838"},"modified":"2018-05-12T16:20:49","modified_gmt":"2018-05-12T20:20:49","slug":"night-shift-not-quite","status":"publish","type":"post","link":"https:\/\/designinglight.com\/?p=838","title":{"rendered":"Night Shift? Not Quite."},"content":{"rendered":"

We’ve all heard about the effect blue light can have on our circadian rhythms. \u00a0It can suppress the release of melatonin, which can delay sleep and reduce sleep quality with possible long-term health consequences. \u00a0Circadian disruption has been associated with depression and increased risk of diseases such as diabetes, obesity and cancer.<\/p>\n

Back in 2016 the AMA released a report<\/a> recommending night-time outdoor lighting have a color temperature no higher than 3000 K to limit night-time exposure to blue light. \u00a0That report was quickly criticized by the Lighting Research Center and the IES, among others, as I noted here<\/a> and here<\/a>. \u00a0One of the key criticisms was that correlated color temperature is a poor measure of spectral content and says nothing about the amount of energy in the wavelength range that affects our circadian rhythms. \u00a0A better measurement is melanopic content, which isn’t discussed in the report.<\/p>\n

Last year Apple unveiled a feature in their OS and iOS called Night Shift. \u00a0When enabled it causes the color of the display to become warmer in the evening. \u00a0The assumption, the same as the AMA’s, is that warmer light has less blue so it won’t impact melatonin production.<\/p>\n

A recently published paper<\/a> in Lighting Research & Technology looked at the effectiveness of Night Shift. \u00a0This preliminary study suggests that “changing the spectral composition of self-luminous displays without changing their brightness settings may be insufficient for preventing impacts on melatonin suppression.” \u00a0Even when Night Shift was used, the devices still suppressed melatonin production. \u00a0The authors noted that, “it is not known how this amount of suppression induces circadian disruption, delays sleep or affects health. \u00a0Larger, more comprehensive epidemiological studies should investigate how the long-term use of these self-luminous displays affects people, especially adolescents and children.”<\/p>\n

While additional studies are clearly needed, it provides additional evidence that lower CCT alone is probably not enough. \u00a0With our display devices we should also lower the brightness.<\/p>\n","protected":false},"excerpt":{"rendered":"

We’ve all heard about the effect blue light can have on our circadian rhythms. \u00a0It can suppress the release of melatonin, which can delay sleep and reduce sleep quality with possible long-term health consequences. \u00a0Circadian disruption has been associated with depression and increased risk of diseases such as diabetes, obesity and cancer. Back in 2016 … Continue reading Night Shift? Not Quite.<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[3],"tags":[29,59],"class_list":["post-838","post","type-post","status-publish","format-standard","hentry","category-health","tag-color-temperature","tag-light-and-health"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_shortlink":"https:\/\/wp.me\/p4gZSw-dw","jetpack_sharing_enabled":true,"jetpack_likes_enabled":true,"jetpack-related-posts":[{"id":223,"url":"https:\/\/designinglight.com\/?p=223","url_meta":{"origin":838,"position":0},"title":"Circadian Lighting","author":"Jason Livingston","date":"October 4, 2014","format":false,"excerpt":"A recent article in The Wall Street Journal discussed the possibilities and benefits of lighting systems that shift color to mimic the changes in daylight. It\u2019s a complicated subject so it\u2019s not surprising that some of what\u2019s reported is inaccurate, so let me clarify a few things. First, our current\u2026","rel":"","context":"In "Health"","block_context":{"text":"Health","link":"https:\/\/designinglight.com\/?cat=3"},"img":{"alt_text":"ipRGC (black), rod (blue), and cone (red) sensitivity curves","src":"https:\/\/i0.wp.com\/designinglight.com\/wp-content\/uploads\/2014\/10\/VLambda-phot-scot-circ-300x254.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]},{"id":692,"url":"https:\/\/designinglight.com\/?p=692","url_meta":{"origin":838,"position":1},"title":"LRC Responds to AMA on LEDs","author":"Jason Livingston","date":"March 27, 2017","format":false,"excerpt":"You may remember that in June of last year the American Medical Association (AMA) released a report called \u201cHuman and Environmental Effects of Light Emitting Diode (LED) Community Lighting.\u201d The report made some noise in the general press because it supported the idea that blue light from blue-pump white LEDs\u2026","rel":"","context":"In "Color"","block_context":{"text":"Color","link":"https:\/\/designinglight.com\/?cat=12"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":738,"url":"https:\/\/designinglight.com\/?p=738","url_meta":{"origin":838,"position":2},"title":"IES Disagrees With AMA on Night Time Outdoor Lighting","author":"Jason Livingston","date":"June 28, 2017","format":false,"excerpt":"Last year the AMA issued Policy H-135.927\u00a0Human and Environmental Effects of Light Emitting Diode (LED) Community Lighting, which recommended, among other things, that LED outdoor lighting should have a CCT of 3000 K or below. \u00a0The AMA made this recommendation thinking that lower correlated color temperatures contain less blue light,\u2026","rel":"","context":"In "Color"","block_context":{"text":"Color","link":"https:\/\/designinglight.com\/?cat=12"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":2910,"url":"https:\/\/designinglight.com\/?p=2910","url_meta":{"origin":838,"position":3},"title":"CCT Doesn’t Predict Circadian Impact","author":"Jason Livingston","date":"January 2, 2023","format":false,"excerpt":"Two of my IES Color Committee friends and colleagues, Tony Esposito and Kevin Houser, have just published a paper in Scientific Reports that looks at the common assumption that CCT can be used to assess circadian entrainment and other biological impacts of light. The assumption by many is that high\u2026","rel":"","context":"In "Calculations"","block_context":{"text":"Calculations","link":"https:\/\/designinglight.com\/?cat=6"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":203,"url":"https:\/\/designinglight.com\/?p=203","url_meta":{"origin":838,"position":4},"title":"Light and Health","author":"Jason Livingston","date":"July 28, 2014","format":false,"excerpt":"The DOE has recently published a fact sheet titled Lighting for Health: LEDs in the New Age of Illumination.\u00a0\u00a0 It summarizes the Trends in Neuroscience January 2014 article Measuring and Using Light in the Melanopsin Age.\u00a0 Both publications explain the current understanding of our visual and nonvisual response to light.\u2026","rel":"","context":"In "Health"","block_context":{"text":"Health","link":"https:\/\/designinglight.com\/?cat=3"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":592,"url":"https:\/\/designinglight.com\/?p=592","url_meta":{"origin":838,"position":5},"title":"Who Needs A Lighting Designer? Museums and Galleries!","author":"Jason Livingston","date":"January 28, 2016","format":false,"excerpt":"A few weeks ago I gave a three-hour seminar on lighting museums and galleries to the graduate students in an art curating program at a university here in New York. Condensing everything I\u2019d like to say into less than three hours was tough. The two big questions were what to\u2026","rel":"","context":"In "Color"","block_context":{"text":"Color","link":"https:\/\/designinglight.com\/?cat=12"},"img":{"alt_text":"Illuminated with Warm White Fluorescent Lamp","src":"https:\/\/i0.wp.com\/designinglight.com\/wp-content\/uploads\/2014\/11\/Color-Shift-3000K-Fl-300x189.jpg?resize=350%2C200&ssl=1","width":350,"height":200},"classes":[]}],"_links":{"self":[{"href":"https:\/\/designinglight.com\/index.php?rest_route=\/wp\/v2\/posts\/838","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/designinglight.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/designinglight.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/designinglight.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/designinglight.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=838"}],"version-history":[{"count":2,"href":"https:\/\/designinglight.com\/index.php?rest_route=\/wp\/v2\/posts\/838\/revisions"}],"predecessor-version":[{"id":841,"href":"https:\/\/designinglight.com\/index.php?rest_route=\/wp\/v2\/posts\/838\/revisions\/841"}],"wp:attachment":[{"href":"https:\/\/designinglight.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=838"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/designinglight.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=838"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/designinglight.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=838"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}