Fatigued? Overworked? Maybe . . . or it could be you're just underlit. Eye strain and low productivity can be blamed on many things, but the real culprit may be lack of good lighting. Pam Horner, manager of general lighting education for Osram Sylvania, a manufacturer of lighting products based in Danvers, Massachusetts, reveals homebased business owners' most common lighting mistakes, and shows you how to avoid them:

"I've converted an existing space into a home office and am making do with lighting fixtures originally intended for other uses." Purchase new lighting for your home office and use a layering effect. For example, achieve a relatively low level of general or "ambient" lighting with fluorescent fixtures: They won't flicker, they're cooler to operate, they last longer than incandescent sources (the kind you find throughout your home) and they save energy. Try indirect lighting fixtures to create this ambient layer. Build a simple shelf to accommodate a fluorescent strip light, and use fluorescent torchieres for spaces that have no ceiling or wall access for electrical service. Then add task lighting where needed.

"I've incorrectly placed my computers, creating a glare from windows and electric light sources." To avoid any glare or eye strain, don't place the computer monitor where it can reflect a window, bright surface or lamp. The reflections make it hard to see the screen, and your eyes are constantly trying to adjust between the nearby text and the reflected objects far away.

"I didn't consider my business tasks when selecting my lighting." Always begin by identifying the most important areas and visual tasks in your office. Consider each area: Do you frequently read sales reports at your desk? Is filing important? Is much of your time spent at the computer? Task lighting helps for reading papers and working with the keyboard, and it can be installed in the form of halogen or fluorescent self-lighted bookstands, adjustable-arm desk lights or under-cabinet lighting.