Why we need to discuss Digital Eye Health & Blue Light Protection
In the last decade, we changed from using light to see the world to staring into LED (light-emitting diode) illuminated devices to connect with the world.1 Today, eye doctors are seeing patients with more digital eye health symptoms: eye strain, fatigue, dry eyes, headache, blurred vision, neck/shoulder/back pain2 and sleep issues.3
In the first four issues of the Blue Light Bulletin, Dr. Allan Barker reviewed blue light exposure assessment, the importance of patient education, and other blue light effects.4 In the next six issues, I will survey the relationship of blue light with the following topics: improving sleep/reducing digital eye strain; carotenoids and MPOD; dry eye disease; macular pigment protection; myopia control; and optometrists’ role as Ocular Health Protector.
In his most recent interview with WebMD, “Is Blue Light Bad for Your Health”, Dr. Czeisler, director of sleep medicine at Harvard Medical School, explains, "The more research we do, the more evidence we have that excess artificial light at night can have a profound, deleterious effect on many aspects of human health. It is a growing public health concern.”5 Light is the most important synchronizer of human circadian rhythms, or biological clocks.5 Hours of exposure to LED digital devices affect the natural biological clock.3
Human retina has three types of photoreceptors: rods (rhodopsin), cones (photopsin), and intrinsically photosensitive retinal ganglion cells (ipRGCs).6 Rods and cones are responsible for image-forming vision. The non-image forming ipRGCs modulate sleep,7,8,9,10 mood and learning,11 and may be involved in regulation of metabolism.12
Figure 1. Image from The Good Blue and Chronobiology: Light and Non-visual Functions, Points de Vue, International Review of Ophthalmic Optics, May 2013 by Claude Gronfier, PhD.
The circadian retinal photo pigment (ipRGC) is melanopsin13,14,15 with absorption peak at 470–480 nm.16,17,18 These RGCs express pituitary adenylate cyclase-activating polypeptide (PACAP)19 and form the retinohypothalamic tract (RHT).20 The RHT is responsible for conveying the light information from RGCs to the part of the brain that controls circadian rhythms.21,22 Staring into digital devices with blue light emission peak at 440-450 nm23 disrupts the biological clock,3 affects melatonin production,24 and leads to sleep issues.25
Eye doctors can prescribe the following optical solutions to help people sleep better and experience less digital eye strain:
1. Combine anti-fatigue (younger than 40), progressive (older than 40), or computer only lens designs with selective blue light1 blocking
2. Use apps or light sources that shift to longer wavelength lights in the evenings3
3. Switch to glasses with blue light protection 1-2 hours before bedtime (for contact lens wearers)
4. Follow Sleep Hygiene tips26,27 and avoid digital devices before bedtime1,24,25
Article sponsored by Essilor.
1. “Ocular Light Toxicity and the Requirement for Protection”. Points de Vue, International Review of Ophthalmic Optics. April 2017.
2. “Digital Eye Strain”. The Vision Council. 2017. https://www.thevisioncouncil.org/content/digital-eye-strain
3. Tosini G, Ferguson I, Tsubota K. Effects of blue light on the circadian system and eye physiology. Molecular Vision. 2016;22:61-72.
4. Allan Barker, OD. Blue Light Bulletin. Optometric Management. March 2017-June 2017. http://www.optometricmanagement.com/newsletters/blue-light-bulletin
5. Lisa Marshall. Is Blue Light Bad For Your Health? WebMD Health News. June 19, 2017. http://www.webmd.com/sleep-disorders/news/20170619/is-blue-light-bad-for-your-health
6. Yamazaki S, Goto M, Menaker M. No evidence for extraocular photoreceptors in the circadian system of the Syrian hamster. J Biol Rhythms. 1999; 14:197-201. [PMID: 10452331].
7. Lupi D, Oster H, Thompson S, Foster RG. The acute light induction of sleep is mediated by OPN4-based photoreception. Nat Neurosci. 2008; 11:1068-73. [PMID: 19160505].
8. Altimus CM, Güler AD, Villa KL, McNeill DS, Legates TA, Hattar S. Rods-cones and melanopsin detect light and dark to modulate sleep independent of image formation. Proc Natl Acad Sci USA. 2008; 105:19998-20003. [PMID: 19060203].
9. Tsai JW, Hannibal J, Hagiwara G, Colas D, Ruppert E, Ruby NF, Heller HC, Franken P, Bourgin P. Melanopsin as a sleep modulator: circadian gating of the direct effects of light on sleep and altered sleep homeostasis in Opn4 (−/−) mice. PLoS Biol. 2009; 7:e1000125-[PMID: 19513122].
10. Muindi F, Zeitzer JM, Colas D, Heller HC. The acute effects of light on murine sleep during the dark phase: importance of melanopsin for maintenance of light-induced sleep. Eur J Neurosci. 2013; 37:1727-36. [PMID: 23510299].
11. LeGates TA, Altimus CM, Wang H, Lee HK, Yang S, Zhao H, Kirkwood A, Weber ET, Hattar S. Aberrant light directly impairs mood and learning through melanopsin-expressing neurons. Nature. 2012; 491:594-8. [PMID: 23151476].
12. Aytürk DG, Castrucci AM, Carr DE, Keller SR, Provencio I. Lack of Melanopsin Is Associated with Extreme Weight Loss in Mice upon Dietary Challenge. PLoS One. 2015; 10:e0127031-[PMID: 26011287].
13. Provencio I, Jiang G, DeGrip WJ, Hayes WP, Rollag MD. Melanopsin: An opsin in melanophores, brain, and eye. Proc Natl Acad Sci USA. 1998; 95:340-5. [PMID: 9419377].
14. Provencio I, Rodriguez IR, Jiang G, Hayes WP, Moreira EF, Rollag MD. A novel human opsin in the inner retina. J Neurosci. 2000; 20:600-5. [PMID: 10632589].
15. Bellingham J, Chaurasia SS, Melyan Z, Liu C, Cameron MA, Tarttelin EE, Iuvone PM, Hankins MW, Tosini G, Lucas RJ. Evolution of melanopsin photoreceptors: Discovery and characterization of a new melanopsin gene in non-mammalian vertebrates. PLoS Biol. 2006; 4:e254-[PMID: 16856781].
16. Berson DM, Dunn FA, Takao M. Phototransduction by ganglion cells innervating the circadian pacemaker. Science. 2002; 295:1070-3. [PMID: 11834835].
17. Qiu X, Kumbalasiri T, Carlson SM, Wong KY, Krishna V, Provencio I, Berson DM. Induction of photosensitivity by heterologous expression of melanopsin. Nature. 2005; 433:745-9. [PMID: 15674243].
18. Bailes HJ, Lucas RJ. (2013. Human melanopsin forms a pigment maximally sensitive to blue light (λmax ≈ 479 nm. supporting activation of G(q/11. and G(i/o. signaling cascades. Proc Biol Sci. 2013; 280:20122987-[PMID: 23554393].
19. Hannibal J, Hindersson P, Knudsen SM, Georg B, Fahrenkrug J. The photopigment melanopsin is exclusively present in pituitary adenylate cyclase-activating polypeptide-containing retinal ganglion cells of the retinohypothalamic tract. J Neurosci. 2002; 22:RC191-[PMID: 11756521].
20. Gooley JJ, Lu J, Chou TC, Scammell TE, Saper CB. Melanopsin in cells of origin of the retinohypothalamic tract. Nat Neurosci. 2001; 4:1165-[PMID: 11713469].
21. Moore RY, Lenn NJ. A retinohypothalamic projection in the rat. J Comp Neurol. 1972; 146:1-14. [PMID: 4116104].
22. Johnson RF, Moore RY, Morin LP. Loss of entrainment and anatomical plasticity after lesions of the hamster retinohypothalamic tract. Brain Res. 1988; 460:297-313. [PMID: 2465060].
23. Nakamura S, Chichibu S. “Introduction to Nitride Semiconductor Blue Lasers and Light Emitting Diodes”. 2000; CRC Press; 1st 386 pages.
24. Brittany Wood, Mark S. Rea, Barbara Plitnick, Mariana G. Figueiro, Light level and duration of exposure determine the impact of self-luminous tablets on melatonin suppression, Applied Ergonomics, Volume 44, Issue 2, 2013, Pages 237-240, ISSN 0003-6870, http://dx.doi.org/10.1016/j.apergo.2012.07.008.
25. Chang AM, Aeschbach D, Duffy JF, Czeisler CA. Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness. Proc Natl Acad Sci U S A. 2015 Jan 27;112(4):1232-7. doi: 10.1073/pnas.1418490112. Epub 2014 Dec 22.
26. Sleep Hygiene Tips. American Sleep Association. 2017. https://www.sleepassociation.org/patients-general-public/insomnia/sleep-hygiene-tips/
27. Roy H Lubit, Curley L Bonds, II, Michael A Lucia, Iqbal Ahmed. Sleep Disorders Treatment & Management. MedScape. Jan 28, 2015. http://emedicine.medscape.com/article/287104-treatment#d9
Dr. Bridgitte Shen Lee earned an optometry degree from University of Houston College of Optometry in 1998. She is the CEO of Vision Optique and iTravelCE. Dr. Shen Lee writes and lectures on the topics of Digital Eye Health, Dry Eye Disease, Health Care Social Media, and Aesthetic Optometry.
Financial Disclosure: Speaker/consultant/advisor for Johnson & Johnson Vision, Shire, Bausch & Lomb, Essilor, Luxottica, OCuSOFT, and Guardion Health Sciences