Blue light has been linked to all sorts of issues, from causing digital eye strain to making us blind. There’s a lot of conflicting evidence, however, about exactly how harmful (or not) it really is.

The American Academy of Ophthalmology says that there’s no evidence that the blue light specifically given off by screens will cause eye damage, as we are exposed to blue light all day from the sun.

Talking to CNET, Dr. Raj Maturi, a clinical spokesperson for the American Academy of Ophthalmology, explained, “During the day, you get 10 times as much blue light from the sun as you do from your computer screen. Our bodies have evolved to deal with this light.”

However, research compiled by the AOA indicates that prolonged exposure to blue light (such as sitting in front of a computer all day) might cause damage to your retina — the innermost layer of your eye that sends signals to your brain to process what you are seeing.

Prevent Blindness, a nonprofit dedicated to mitigating vision loss, also says that early research suggests that blue light can contribute to eye strain.

What are blue-light blocking glasses?

Blue-light blocking glasses have filters in their lenses that block or absorb blue light, and in some cases UV light, from getting through. That means if you use these glasses when looking at a screen, especially after dark, they can help reduce exposure to blue light waves that can keep you awake.

Many blue-light blocking glasses you can buy also claim to help reduce eye strain.

Most are meant to be worn during the day while working in front of a computer, and at night to prevent the blue light from screens from keeping us awake.