Can blue light damage your eyes? This is an important question considering the amount of time we spend on our digital devices. In fact, American adults spend more than 11 hours per day watching, reading, listening or simply interacting with media, according to a new study by market-research group Nielsen.[i] The short answer to this question presently is no. There is no scientific evidence to date that blue light from digital devices is harmful to the eyes. That said, the effects of blue light are still being researched.
What is blue light?
Blue light is a part of the visible light spectrum which is situated very close to UV, or ultraviolet, radiation. Blue light has a shorter wavelength, and therefore a longer frequency than red light on the other end of the spectrum. The longer the frequency, the higher the energy. What this means is that blue light emits a lot of energy.
When are you exposed to blue light?
Sunlight is the main source of blue light. Other sources include fluorescent light, LED light, flat screen LED televisions, computer monitors, tablets and smart phones.
The blue light exposure from digital screens is minimal compared to the amount we get from sunlight. However, the close proximity of screens combined with longer exposure times is what creates the cause for concern and likely fuels the research on the potentially harmful effects of blue light.
How does blue light affect the eyes?
Blue light, as well as other light in the visible light spectrum, passes through the cornea and the natural lens of the eye, on its way to the retina. In order to see clearly, light needs to come into focus on the retina. Since blue light has a shorter wavelength, instead of coming into focus on the retina, it is slightly defocused in front of the retina. This, combined with the decrease in contrast that blue light can cause on digital devices, can create eye strain.
What can I do to minimize the eyestrain caused by digital device use?
Decreasing your screen time and taking regular breaks is really the only sure way to decrease eyestrain caused by digital device use. You can find a more detailed guide to decreasing eyestrain in our blog post: Dr. Mandel’s Reading and Computer Tips. Although there are glasses that claim to protect your eyes against blue light, it’s unclear whether or not these are effective.
Although currently there is no scientific evidence proving that blue light is harmful to the eyes, there are other negative effects of blue light. One of the main side effects of blue light exposure near bedtime is interruption of the sleep-wake cycle, which can cause trouble sleeping. There are also benefits of blue light, particularly from sunlight, such as helping memory and boosting cognitive function. It can also help elevate your mood. So, the bottom line as with most things is moderation.