The Bad (and the Good!) About Blue Light

If you’re like most Americans, you’re probably spending more time exposed to “blue light” than you think. Blue light is the light emitted by your computer screen or digital devices. While it may not appear necessarily “blue” to you, this identifier is used to denote the wavelength of the light rays and the amount of energy contained within them.

For example, light from the sun contains red, orange, yellow, green and blue rays, which combine into “white light.” Infrared light – like those you may see at your dermatologist office or used in a heat lamp to keep food warm is – you guessed it – red light. Blue light contains the shorter wavelengths of light and therefore more energy. A step beyond blue light is ultraviolet light, which you’re likely familiar with.

If you’re like the rest of us modern Americans who find ourselves glued to our computers, tablets, phones and devices, there are a few things you should know about this blue light.

It’s all around you.

…particularly if you love your electronics. Of course, you’re exposed to blue light every time you look at a computer screen, smartphone or other digital device. But the amount of blue light you’re exposed to from electronics is actually just a fraction of what you’re exposed to simply from living under the sun.

That said, you’re not holding the sun up to your face constantly, so the blue light is more focused on your eyes (and vice versa) than when you’re outside on a typical day.

It’s why the sky looks blue

The short wavelengths in blue light means it scatters more easily than other visible light rays. That’s why, when the sun is shining, it makes the sky appear blue rather than red, orange, yellow or any other light wavelength emitted by the sun.

Any light that makes the sky look so beautiful can’t be bad, right? Well, maybe…

Your eye doesn’t block blue light very well

Your eyes are really good at protecting themselves, but that doesn’t mean they can protect themselves from blue light – especially when you’re exposing yourself to it all the time. Within your eyes, your cornea and lens work together to block UV radiation – and they’re really good at it. In fact, your retina winds up exposed to less than one percent of the UV radiation to which you’re exposed – even if you’re not wearing UV-blocking sunglasses (not to say that sunglasses aren’t a crucial accessory when you’re looking to protect your eyes!).

Unfortunately, your lens and cornea don’t block blue light in the same way, so most – if not all – blue light passes straight through your cornea and lens and reaches the retina.

It could put you at risk for macular degeneration

Because that blue light is reaching your retina, it can damage the light-sensitive cells housed there. This causes vision changes that are similar to macular degeneration, one of the leading causes of vision loss and even blindness.

It’s just painful

If you’ve ever nursed a headache after hours spent in front of the computer, you’re certainly not alone. Staring at that short-wavelength, high-energy blue light creates “visual noise” that reduced contrast and makes your eyes strain.

Eye strain can also contribute to dry eyes and even prescription changes, so if you’re concerned with the amount of time you’re spending staring at a screen, it’s important to talk to your eye doctor.

You may need extra protection

If you’ve had cataract surgery, you may need to be especially wary of blue light. As your eyes age, your lens naturally begin to block some blue light, particularly the blue light that causes the most damage to your retina. That said, if you have cataract surgery, your surgeon may use a type of intraocular lens (IOL) to replace your natural lens, which may not offer you the blue light protection you need.

Talk to your surgeon or eye doctor about ways you can protect your eyes from blue light.