Goodbye, Red Eye

Recently, I found myself under pressure to complete a project that involved spending a great deal of time working on the computer, poring over graphics, and proofreading small print. Although I took breaks, I developed a nagging headache and my eyes were burning, bloodshot, and blurry.

“You look as though you haven’t slept in days,” observed my client Reinhold, when meeting with me to go over the work he had commissioned. “Are you feeling okay?” he asked. I had to admit that I was feeling drained and exhausted.

“What about the lighting around your work station?” inquired Reinhold, who related that he had experienced similar symptoms and eventually found relief when he altered the lighting in his work area. “I tested a variety of lights,” Reinhold continued, “but eventually I opted for full-spectrum lighting because it really helped me when I worked with graphics and print applications.”

Maybe Reinhold had a point–I’d noticed that it was sometimes difficult to see my work. “Nothing ventured, nothing gained,” I opined, and I accepted Reinhold’s suggestion.

What is Full-Spectrum Lighting?

In the 1960s Dr. John Ott first coined the term full-spectrum to describe electric light sources that simulate the visible and ultraviolet spectrum of natural light. However, a 2003 report by the Lighting Research Center in Troy, New York, discovered that “different companies have different ideas about what constitutes a full-spectrum light source, and what it is about full-spectrum light that yields the claimed benefits.”

After surveying 250 lighting professionals, the report’s writers determined, “The term full-spectrum is not a technical term, but rather a marketing term implying a smooth and continuous spectral power distribution without the spikes and troughs in radiant energy common with most discharge light sources (for example, fluorescent and metal halide).” Peter Boyce, the centre’s professor emeritus, added, “There is also an operational definition which says that a full-spectrum lamp has some energy in all visible wavelengths, has a correlated colour temperature of at least 5,000 K (Kelvin), and some UV emission.”

Let There be Light

According to Stefan Graf, in a November 2005 article in Buildings, “The only real full-spectrum source is the sun...A full-spectrum lighting system, like the sun, would equally deliver all of the frequencies of light…Fluorescent light sources that attempt to do that still have peaks and valleys.” Graf suggests that consumers look into the fluorescent light source’s spectral energy distribution (SED)/spectral power distribution (SPD) charts to determine whether some frequencies are missing or others are more frequent. As well, the lamp’s colour rendering index (CRI) rating, which indicates how accurately a light source renders an object’s exact colour, should be 90 or higher (out of 100).

Seeing is Believing

As I delved into the topic of full-spectrum light sources, it became apparent that I would need to experience different light sources under circumstances similar to my work area.

Since Reinhold was the one who had originally piqued my interest in full-spectrum lighting, I asked him if he would care to join me as I tested lighting systems. Reinhold said he had been thinking about upgrading his lighting, and he was interested in investigating the latest innovations. As we finalized our plans to meet, Reinhold stated, “Hopefully this will put an end to your red eyes and I won’t have to feel guilty about sending more work your way.”