It’s January, and in the northern hemisphere, that means the days are short, the office lights feel harsh, and that last cup of coffee just isn’t hitting the way it used to. But why do we feel so unfocused this time of year? As optical professionals, we know light! We know its wavelengths, its refractive power, and its profound effect on our circadian rhythm. Typically, when we talk about light and our circadian rhythm, we’re focused on the high energy visible (HEV) blue light emitted by...