Eye strain is becoming more common as adults -- and children -- spend a significant amount of time with their eyes focused on digital screens, whether it be computer monitors, tablets or smart phones. Other factors contribute to eye strain, though, and lighting is one of them. For example, fluorescent lights, a common form of illumination, may lead to eye strain, particularly if the lighting is too bright or too dim.
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Eye strain is not a condition, but a sign that the nerves and muscles in the eyes need a break. Common symptoms include burning, stinging or watery eyes. Sometimes this eye strain can lead to difficulty focusing on objects or words, or cause an increased sensitivity to light or pain behind the eyes. Spending hours on a computer or digital screen without rest is a leading cause of eye strain. But these eye symptoms can occur with reading, sewing, drawing, driving or any time the eyes are focused on a single task for a long period of time. Other factors that aggravate eye strain include exposure to dry indoor air, and being in an area where the lighting is harsh and bright -- or not bright enough.
During the energy crisis of the 1970's, fluorescent lamps largely replaced traditional, or incandescent lights, as fluorescent lights use 25 to 35 percent less energy for the same amount of light, and last up to 10 times longer. Despite today's emphasis on LED (light-emitting diode) lighting, fluorescent lighting is still in place in many homes, offices and commercial buildings. Almost as long as fluorescent lights have been in use, safety concerns have persisted. One safety question is if the ultraviolet (UV) radiation emitted by these lights causes health problems, including eye strain. Although there is a lack of research examining this safety concern, the Food and Drug Administration reports the UV exposure from these lights falls below the level of concern for normal, healthy individuals.
The Flicker Effect
Early applications of fluorescent lights were plagued by some technical problems. Most notably, they buzzed, flickered and emitted blue-green light, and these issues prompted common complaints of migraines and eye strain. Newer, high-frequency fluorescent lights do not noticeably flicker or buzz, and illuminate in colors that more closely mimic outdoor light, which is easier on vision. One small study suggests these newer lights are beneficial, or at least less problematic, noting a 50 percent drop in complaints of eye strain and headaches from workers after lighting was switched from older, low-frequency fluorescent lights to high-frequency lights.
The Brightness Impact
Historically, indoor lighting was designed to be bright enough to provide light for paper-based work -- which is too harsh and bright to comfortably read self-illuminating computer screens. Although newer, high-frequency fluorescent lights are less likely to cause eye strain, any type of lighting has the potential to be too bright, contributing to eye strain. Indoor lighting needs be adjusted to avoid excess glare from lights or windows, and to avoid too dim of lighting -- which can also lead to eye strain. In fact, ambient light levels for computerized workplaces should be about half the levels that have been traditionally used, incorporating additional task lighting as needed. Although fluorescent lights are often blamed for eye strain, even glare from windows or inadequate lighting on digital screens can lead to eye strain.
Preventing Eye Strain
Eye strain will usually go away once you remove the source of the problem. If you are having eye strain at work, talk to your manager about having an ergonomic evaluation in order to identify ways to reduce glare, improve lighting and modify positions of your desk, monitor and chair to optimize vision and reduce eye strain. At home, avoid viewing digital screens in bright rooms, and use floor or desk lamps if needed for indirect lighting. When reading or viewing a digital screen, give your eyes a rest every 20 minutes, by changing tasks, taking a walk, or simply resting your eyes. Blink often to moisten your eyes, and use artificial tears if needed to counter dry eyes. Keep indoor air from getting too dry by using a humidifier in the winter months. Also, see an eye doctor if you suspect your vision needs correcting, and talk with your doctor if you have an eye condition that is aggravated by your workplace or home lighting.
Reviewed by Kay Peck, MPH RD
REFERENCES & RESOURCES
- American Optometric Association: Computer Vision Syndrome
- Workplace Health and Safety: Visual Ergonomics in the Workplace
- U.S. Food and Drug Administration: Radiation Emitting Products: Compact Fluorescent Lamps (CFLs) – Fact Sheet/FAQ
- Lighting Research and Technology: Fluorescent Lighting, Headaches and Eyestrain
- American Journal of Public Health: Eye Disease Resulting From Increased Use of Fluorescent Lighting as a Climate Change Mitigation Strategy
- OSHA Ergonomic Solutions: Lighting, Glare & Ventilation