What is blue light?

Blue light is a type of light within the visible light spectrum.  Of all the lights in that spectrum, blue light has the highest energy.  Blue light is everywhere.  Outdoors, natural sunlight is the main source of blue light. Indoors, there are many sources of man-made blue light, such as fluorescent and LED bulbs, flat screen TVs, computer screens, and even phone screens.

Some degree of exposure to blue light is essential for good health.  Research has shown that blue light boosts alertness, elevates mood, and helps cognitive function.  Blue light is even used to treat patients with seasonal affective disorder (SAD).  In addition, blue light is very important in regulating circadian rhythm – the body’s natural wakefulness and sleep cycle.

How does blue light affect your eyes and health?

As it turns out, the eye is not very good at blocking blue light. Virtually all the blue light that enters the eye passes through the anterior structures (the cornea and lens) and reaches the retina (the inner lining of the back of the eye). While the amount of blue light emitted by our devices is small compared to that emitted by the sun, the amount of time spent using these devices and the proximity of the screen to the user’s face have raised concerns about cumulative exposure.

Because of its high energy and short wavelength, blue light scatters more easily than other types of visible light.  That means it’s not as easily focused by our eyes. When looking at computer screens and other digital devices that emit significant amounts of blue light, this unfocused visual “noise” reduces contrast and can contribute to eye strain.  Too much blue light late at night (from reading a novel on a tablet, or being on our phones) can also affect our natural circadian rhythm. This can lead to sleepless nights and daytime fatigue.  More seriously,  laboratory studies have shown that excessive exposure to blue light can damage light-sensitive cells in the retina.  This can lead to changes that resemble those seen in macular degeneration, which can lead to visual loss.

How to Protect Your Eyes from Blue Light

Whether natural or artificial, blue light is hard to avoid. However, you can protect your eyes with different kinds of blue light filters. Yellow-tinted computer glasses, for example, block blue light and increase ocular comfort.  Alternatively, you can attach a protective screen directly to your computer or phone screen. And, since blue light can cause more damage the closer it is to your eyes, it’s advisable to make an effort to hold your phone at a safe distance from your eyes.

In addition to screen filters, there are also settings and apps you can install on your phone to reduce blue light levels. On iPhones, the Night Shift mode reduces blue light. On Androids, you can enable Night Mode to do the same thing. These settings don’t eliminate blue light completely, but they do reduce its effects, especially at night.

At Broberg Eye Care, we are committed to helping you take care of your eyes in order to keep them as healthy as possible. Schedule an appointment today!