Sales of Blue-Light Blocking Glasses Soar after Harvard Heath Letter Article

Share Article

“Light at night is bad for health” is the opening statement in the article in Harvard Medical School’s Health Letter (1) that identifies the problem as the blue rays from ordinary light bulbs. Photonic Developments LLC sells eyeglasses that block blue light and light bulbs that don’t produce blue light. Use of these products solves this serious health problem that affects everyone.

The Harvard Medical School Health Letter this month features an article that reveals that exposing the eyes to ordinary light at night has been shown by Harvard researchers to reduce the production of melatonin. It also disrupts the circadian rhythm. This can lead to problems sleeping, to diabetes, obesity, heart disease and breast and prostate cancer. Sleep is a major, widespread casualty of exposing the eyes to ordinary light in the evening and during the night.

Recently developed electronic devices have glowing screens that are used close to the face. The light from them is rich in blue rays. Modern high efficiency light bulbs like compact fluorescent and LED lights also produce lots of blue light. Even the old fashioned incandescent light bulbs produce significant amounts of blue light. Many people use these glowing electronic devices in bed before trying to go to sleep. Filters for the screens of electronic devices, computers and TV’s are available at the website as well as blue-light blocking glasses and light bulbs.

Some glasses that are sold as “Blue Blockers” not only block the blue rays but much of the other colors as well. They are designed to be used as sunglasses and are too dark to be used indoors at night. The ones from only block the blue light known to suppress melatonin and transmit more than 90% of the other colors. This means normal evening activities like working on a computer or reading or watching TV can go on as usual when wearing them.

The article points out that Harvard scientist, Dr. Charles Czeisler showed in 1981 (2) that exposing the eyes to daylight early in the morning keeps a person’s internal clock aligned with the clock on the wall. Exposing the eyes to light, especially blue light in the hours before bedtime delays the production of melatonin and tends to shift the internal clock to a later hour.

A Harvard study (3) found the frequent shifting of the cycle increased blood sugar levels, throwing the subjects into a pre-diabetic state. The levels of leptin, a hormone that leaves people feeling full after a meal, went down. This leads toward obesity. This disruption of the circadian cycle and the resulting damage to sleep and health may be avoided by the use of the LowBlueLight light bulbs or eyeglasses.

These products were developed in 2005 at John Carroll University in the Lighting Innovations Institute by a team of physicists who recognized that using ordinary light bubs at night was a health problem that needed a solution. Since then, thousands of people have purchased these products from the spin off company, Photonic Developments LLC. About 90% find they sleep better when using the glasses or light bulbs that are sold with a money-back guarantee

For information contact Dr. Richard Hansler 216 397 1657 or rhansler(at)jcu(dot)edu.

“Blue Light has a Dark Side” Harvard Medical School Health Letter- May 2012

Photochem Photobiol. 1981 Aug;34(2):239-47.
Entrainment of human circadian rhythms by light-dark cycles: a reassessment.
Czeisler CA, Richardson GS, Zimmerman JC, Moore-Ede MC, Weitzman ED.

Proc Natl Acad Sci U S A. 2009 Mar 17;106(11):4453-8. Epub 2009 Mar 2.
Adverse metabolic and cardiovascular consequences of circadian misalignment.
Scheer FA, Hilton MF, Mantzoros CS, Shea SA.

Share article on social media or email:

View article via:

Pdf Print

Contact Author

Richard Hansler
Visit website