Most people are aware that sunlight contains invisible ultraviolet rays that can harm the skin and eyes. But many people don’t know that the sun’s visible light, primarily blue light, can also damage our eyes and cause macular degeneration. In today’s post, our Raleigh optometrist will explain how blue light, infrared light, and ultraviolet light work, and how they affect our eye health.
Sunlight contains red, orange, yellow, green, blue, and violet rays of light. Combined, this spectrum forms what we call “white light”, or sunlight. The longer a light ray’s wavelength is, the less energy it contains. The shorter a ray’s wavelength, the more energy it contains. This is why red light, which has the longest wavelength, has the least energy. Blue light rays, on the other end of the spectrum, have the shortest wavelengths and the most energy.
Because blue light has a short wavelength and high energy, it scatters more easily than other visible light, and is not as focused. When you’re looking at computer screens and other digital devices that emit significant amounts of blue light, this unfocused visual “noise” reduces contrast and can contribute to digital eye strain. The sunlight we are exposed to every day is also a prime source of blue light. Approximately one-third of all visible light is considered high-energy visible (HEV) or “blue.”
Just beyond the red end of the visible light spectrum are infrared waves, which are too long for us to see. We can feel their heat, however, which is why hunters and movie spies use infrared cameras and sensors to “see” the infrared rays emitted by warm objects and people.
At the other end of the visible spectrum, past the visible blue light, is a light wave that’s too short for us to see. We call these waves blue-violet, or ultraviolet (UV) radiation. Since UV rays have higher energy than visible light rays, high exposure to them can cause suntans, sunburns, and eye damage. When received in moderation, though, UV light also has beneficial effects, such as helping the body manufacture adequate amounts of vitamin D.
If you’re looking for a Raleigh, NC eye doctor, visit to Raleigh Eye Center today. We offer comprehensive eye exams, professional contact and eyeglass fittings, and more. For more information, be sure to check out our website or call us today.