The topic of blue light is growing popular in nearly every channel. Patients, primary care physicians, optometrists, and ophthalmologists have all taken an interest in this seemingly harmless wavelength of light. Paul Chous, MA, OD, FAAO, CDE, has heard the buzz and decided to share his comments about blue light via video. Here’s a quick summary of his thoughts.
Blue Light According to Dr. Chous
With accumulating evidence, Dr. Chous has no doubt that there are harmful consequences to increasing exposure to blue light. He mentions retinal damage first, saying, “Blue light…has cumulative toxicity to the retinal photoreceptors and the retinal pigment epithelium (RPE) cells.” But he takes time to highlight the endocrine effects of the short wavelength light, as well.
Chous cites several studies that prove the negative impact blue light exposure can have on melatonin production and sleep. For example, he names a study that found that limiting screen time an hour before bed increased REM sleep by 11%. He then names a Japanese study that stressed the importance of this finding, saying that an 11% decrease in REM sleep is equal to 15,000 more cardiovascular deaths per year.
These results put a heavy emphasis on turning off devices before bed. But Chous makes a point to say that patients get more blue light exposure from spending just 10 minutes outside, even on a cloudy day, than from digital screens.
Some people believe that blue light, whether from digital devices or the sun, may lead to a greater risk of age-related macular degeneration (AMD). Chous feels there’s not enough evidence to support that theory, though there is a connection. Macular pigment, the “internal sunglasses” that protect the rods and cones from direct photo-toxicity caused by harmful blue light, is often less dense in those with AMD.
Suboptimal macular pigment [left] is less dense, allowing blue light to reach the photoreceptors. Optimal macular pigment [right] blocks the harmful light wave before it reaches the sensitive cells.
Dr. Chous’s Recommendations
- Build patients’ macular pigment.
- Measure macular pigment optical density (MPOD) in practice.
- Encourage patients to limit screen time an hour before bed.
What are your thoughts about blue light?
P.S. It’s Talk Like a Pirate Day! Arrrrggghhh, Matey!