Fluorescent lighting, headaches and eyestrain

Abstract

The weekly incidence of headaches among office workers was compared when the offices were lit by fluorescent lighting where the fluorescent tubes were operated by (a) a conventional switch-start circuit with choke ballast providing illumination that pulsated with a modulation depth of 43-49% and a principal frequency component at 100 Hz; (b) an electronic start circuit with choke ballast giving illumination with similar characteristics; (c) an electronic ballast driving the lamps at about 32 kHz and reducing the 100 Hz modulation to less than 7%. In a double-blind cross-over design, the average incidence of headaches and eyestrain was more than halved under high-frequency lighting. The incidence was unaffected by the speed with which the tubes ignited. Headaches tended to decrease with the height of the office above the ground and thus with increasing natural light. Office occupants chose to switch on the high-frequency lighting for 30% longer on average.

Lighting Quality Contributions from Biopsychological Processes

“…107,108 Two studies have found that increasing the operating frequency of the fluorescent lighting system decreases the incidence of eyestrain, headache, and other asthenopic symptoms. 109,110 In particular, Wilkins et al found that the installation of high-frequency ballasts led to a 50% reduction in the reported incidence of eye-strain and headaches in office workers.…”

96/06101 Modulation of fluorescent light — Flicker rate and light source effects on visual performance and visual comfort

“…(2) If so, this would account for the reduced incidence of headache and eye-strain when electronic ballasts were introduced into offices. (17) The absence of effects on visual comfort in this experiment probably reflects the brief exposure time (8 minutes at most before the administration of the visual comfort measure). All the participants reported being relatively comfortable in both flicker conditions.…”

Revisiting the Performance and Mood Effects of Information About Lighting and Fluorescent Lamp Type

“…The evidence does not support changing fluorescent lamp type as a solution to occupants' problems with fluorescent lighting. Field and laboratory studies have more consistently identified other aspects of the lighting system, such as the flicker rate (Veitch & McColl, 1995;Wilkins, Nimmo-Smith, Slater, & Bedocs, 1989) and luminaire design (Hedge, Sims, & Becker, 1995;Katzev, 1992) as levers for solutions to problems with interior lighting. Future research should focus on understanding these effects to characterise high-quality lit environments that meet human needs.…”