Evaluation of Blue-Light Hazards from Various Light Sources

Abstract

Visible light of short wavelength (blue light) may cause a photochemical injury to the retina, called photoretinitis or blue-light hazard. In this study, various light sources were evaluated for blue-light hazard. These sources include the sun, the arc associated with arc welding and plasma cutting, molten steel, iron and glass, the interior of furnaces, the arc or envelope of discharge lamps, the filament or envelope of incandescent lamps, the envelope of fluorescent lamps and light-emitting diodes. The spectral radiance of each light source was measured, and blue-light effective radiance and the corresponding permissible exposure time per day were calculated in accordance with the ACGIH (American Conference of Governmental Industrial Hygienists) standard. The sun, arc welding, plasma cutting and the arc of discharge lamps were found to have extremely high effective radiances with corresponding permissible exposure times of only 0.6-40 s, suggesting that viewing these light sources is very hazardous to the retina. Other light sources were found to have low effective radiances under the study conditions and would pose no hazard, at least for short exposure times.

Helicobacter pylori in patients can be killed by visible light

“…In an optically clear medium (PBS), this fluence completely eradicated H. pylori producing up to 5 logs of kill in a light-dose dependent manner. Also, the amount of light delivered by our device in this study falls below the threshold limit value for exposure of the eye or the skin published by the American Conference of Governmental Industrial Hygienists [24]. In addition, this dose of light energy and intensity has been demonstrated to be safe, as it falls within the range equivalent to light exposure from endoscopy [25].…”

Photobiological safety of the recently introduced energy efficient household lamps

“…L B -blue-light hazard weighted radiance, After measuring spectral irradiance, the biologically effective values were calculated according to the standard [17].…”

“…Okuno et al [17] have measured various light sources, e.g., welding arc lights, incandescent, halogen, LED, fluorescent and arc lamps, with a conclusion that the lamps used in households have low effective radiance and mean no hazard (at least in the case of short exposure time). Development of manufacturing and spreading new light sources require drawing attention to these questions.…”

Photic Retinopathy After Cataract Surgery in Diabetic Patients

“…On the other hand, retina pigment epithelium and photoreceptors are known to be extremely sensitive to low-wavelength blue light. 32,33 It is a fact that across the visible spectrum, blue light is most detrimental to the retina. Filtration of blue light, therefore, may be logical to prevent the vulnerability of these structures to photic injury, especially when further damage due to compromised blood flow is possible, such as in DM.…”