How Bad Is Blue Light? Local Optometrist Says It Can Be Good For You

SACRAMENTO (CBS13) — Many of us are glued to our screens all day long. From your phone to your computer, they all emit what's called "visible blue light."

When we stare at these for long periods of time, we've been told excessive screen time can be bad for your eyes and brain. But now we're learning its not all bad.

Neighbors in Sacramento told us they were surprised to hear some blue light is actually good for you.

Mark Cota from Sacramento said, "I would be shocked, I would be very shocked. I don't know if I would believe it."

Believe it or not, blue light has benefits, including boosting your mood.

"It helps your natural rhythm, so your sleep, wake cycle and it also can prevent near nearsightedness," said Dr. Melissa Barnett, a principal optometrist at the UC Davis Eye Center.

READ ALSO: 1 In 7 Babies Is Born Underweight, With Dire Consequences For Their Health, Global Study Says

Blue light boosts alertness, helps memory and cognitive function, and elevates mood. It regulates the circadian rhythm, the body's natural wake and sleep cycle.

Sunlight is also important for the growth and development of the eyes and vision in children. Inadequate exposure to blue light can also contribute to nearsightedness.

She says blue light is everywhere.

"The most common source of blue light is sunlight. Blue light is also in fluorescent light, street lights and screens," Barnett said.

But what you've been hearing about it, is true, too much of it can be a bad thing.

"A lot of the talk about blue light is digital eye strain, and how it can affect sleep while on digital devices late at night," Barnett said.

READ: Sheriff: Man Arrested After Slapping Sleeping Girlfriend In Face With Cheeseburger

She also says blue light blockers are trendy now. From glasses to now, contact lenses, with built-in UV protection.

"So people have said they have less eye strain on digital devices," said Dr. Barnett.

She said, moral of this story, a little blue light goes a long way.

"It's really important to know when you're on digital devices all day long to take breaks, every 20 minutes to look away at something that's not digital," Barnett said.

Barnett says the best way to get the "perks" from blue light exposure, is to get outside. You can also protect yourself from "too much" blue light, by setting filters for your smartphone or computer screen.