Is blue light harmful to your eyes?

Having trouble sleeping? If you use your phone around your bedtime, that could be why. Electronic devices emit blue light. It's part of any bright, white light, like the sun. Ashley McCain, a UW Medicine optometrist, explains that, while you could switch your device to “night mode,” it's better to not to use it before going to bed.

There is also concern about whether blue light harms the eyes. McCain says more research needs to be done. If you spend a lot of time on computers or smartphones, your sore, tired, or dry eyes could result from digital eye strain.

"Digital eye strain is basically what will occur to our eyes when we’re looking for an extended period of time at the computer or our devices. We’re really straining to focus due to the contrast that the blue light has," McCain observed. "One of the things is we’re just staring straight at the computer and we’re not thinking to blink. So I always recommend that patients take a break."

While glasses with yellow tints or coatings might help block blue light and improve contrast, the best thing to do is take breaks. A good rule of thumb is 20-20-20: Every 20 minutes, look 20 feet away for 20 seconds.