UPDATES TO OUR COVID-19 POLICY: All encounters, including glasses pick ups, frame selects, exams, and follow-ups, are by appointment only. Please call our text our office and we will work with you to arrange a time for you to come in. Masks are required in our office. If you do not come with a mask or face covering, we will provide you with one before entering. Thank you for your cooperation and patience during this difficult time.

alarm-ringing ambulance angle2 archive arrow-down arrow-left arrow-right arrow-up at-sign baby baby2 bag binoculars book-open book2 bookmark2 bubble calendar-check calendar-empty camera2 cart chart-growth check chevron-down chevron-left chevron-right chevron-up circle-minus circle city clapboard-play clipboard-empty clipboard-text clock clock2 cloud-download cloud-windy cloud clubs cog cross crown cube youtube diamond4 diamonds drop-crossed drop2 earth ellipsis envelope-open envelope exclamation eye-dropper eye facebook file-empty fire flag2 flare foursquare gift glasses google graph hammer-wrench heart-pulse heart home instagram joystick lamp layers lifebuoy link linkedin list lock magic-wand map-marker map medal-empty menu microscope minus moon mustache-glasses paper-plane paperclip papers pen pencil pie-chart pinterest plus-circle plus power printer pushpin question rain reading receipt recycle reminder sad shield-check smartphone smile soccer spades speed-medium spotlights star-empty star-half star store sun-glasses sun tag telephone thumbs-down thumbs-up tree tumblr twitter tiktok wechat user users wheelchair write yelp youtube

How Does Blue Light Affect Our Eyes?

Do you spend a lot of time after the sun goes down looking at a bright screen?

For as long as we’ve been using handheld devices to go online (and probably longer), many of us have had our eyes riveted to bright screens late into the evening. As optometrists, we can’t approve of this bedtime ritual. Screens emit blue light, and that can throw off our internal clocks and possibly affect our eye health.

The Physics of the Visible Light Spectrum

All of the colors we perceive are on the visible light spectrum, just a tiny sliver of the electromagnetic spectrum. Below visible light is infrared radiation and above blue and violet is ultraviolet radiation. Blue and violet are the highest-energy light waves we can see. (Fun fact: the reason the sky looks blue to us is that blue light scatters more easily than other colors. It’s called Rayleigh scattering.)

Our Sleep Cycles Must Battle Artificial Light

In all of human history, the only source of blue light was the sun — up until the last few decades. Our bodies interpret blue light as the signal that it’s time to be awake, so we tend to feel more attentive, remember things more easily, feel better, and have faster reactions during the day. As soon as the sun sets, the lack of blue light signals our bodies that it’s time to wind down for sleep. We aren’t biologically programmed to know the difference between the sun and artificial blue light.

This means that when we light up a screen before bed, we’re blasting our brains with a signal that it’s still time to be awake. Our brains respond by not releasing neurotransmitters that help us sleep, like melatonin. It then takes us longer to fall asleep and we might not enjoy very high-quality sleep. That contributes to a cycle of sleep deprivation and the negative health effects that come with it.

We can minimize these sleep issues by putting our devices away in the last hour before bed, or at least by switching them to night mode so that they don’t emit any blue light and trigger those subconscious signals in our brains.

Blue Light and Eye Health

Many optometrists have been concerned that blue light could be close enough to UV radiation that it might cause similar damage to our eyes, with effects like an increased risk of age-related macular degeneration. However, while our screens give off enough blue light to mess with our sleep schedules, they emit very little compared to the sun, and they don’t emit UV light at all.

The main concern with blue light and eye health is digital eye strain. Spending hours a day staring at a bright screen can make our eyes ache or have difficulty focusing. We could end up having more frequent headaches or struggle to get through our work. We can use tools like screen filters and computer glasses to help block blue light, but a simple trick that can help a lot is the 20-20-20 rule. Every 20 minutes of screentime, take a 20-second break to focus on something at least 20 feet away.

Come to Us With Your Questions About Blue Light

If you’ve experienced symptoms of eye strain during or after using bright screens, we’re happy to discuss it with you and answer your questions. We want to give our patients all the information they need to make smart choices for their eye health.

Each patient we see is a sight for sore eyes!

Top image used under CC0 Public Domain license. Image cropped and modified from original.
The content on this blog is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of qualified health providers with questions you may have regarding medical conditions.