ICNIRP Statement on Short Wavelength Light Exposure from Indoor Artificial Sources and Human Health.

Concerns have been raised about the possibility of effects from exposure to short wavelength light (SWL), defined here as 380-550 nm, on human health. The spectral sensitivity of the human circadian timing system peaks at around 480 nm, much shorter than the peak sensitivity of daytime vision (i.e.

Assessment of adverse events for a home-use intense pulsed light hair removal device using postmarketing surveillance.

Background And Objectives: Home-use intense pulsed light (IPL) hair removal devices are convenient for consumers. Consumer safety associated with home-use IPL devices, however, remains a subject of interest. In this descriptive analysis, we assessed the most commonly reported adverse events (AEs) for a home-use IPL device from postmarketing surveillance and qualitatively compared these with AEs from clinical studies and medical device reports of home-use IPL treatments.

The potential 'blue light hazard' from LED headlamps.

Unlabelled: Many dental personnel use light-emitting diode (LED) headlamps for hours every day. The potential retinal 'blue light hazard' from these white light headlamps is unknown.

Methods: The spectral radiant powers received from direct and indirect viewing of an electronic tablet, an LED curing light, a halogen headlamp, and 6 brands of LED headlamps were measured using integrating spheres attached to fiberoptic spectroradiometers.

Threshold Ocular Exposure to Near Infrared Radiation for Causing Acute Opacification in the Rabbit Lens.

Surveys and epidemiological studies have reported an increased prevalence of cataracts in the glass and steel industries, which are associated with exposure to intense infrared radiation (IR). Indeed, animal studies have demonstrated that IR exposure can produce acute changes in the crystalline lens that are likely to lead to cataract formation. However, little is known about threshold IR exposure for causing acute cataractous changes, which is important in the prevention of IR-induced cataract, especially as a basis for short-term IR exposure limits.

UV Index Does Not Predict Ocular Ultraviolet Exposure.

Purpose: The ultraviolet index (UVI), available online, is an international linear scale of levels from 0 to 13+ that warns about the risk of sunburn; however, it does not address the risk to eyes. Our purpose was to develop a useful instrument to warn the public against ocular ultraviolet (OUV) exposure and to serve as a tool for researching UV-induced ocular diseases.

Methods: A rotating model head that included ultraviolet B (UVB) sensors documented UV irradiance at the crown and at the eyes spanning eight azimuths from sunrise to sunset under different climatic conditions in each season.

Optical performance of welding curtains and existing standards.

Welding curtains and screens are intended to protect workers, other than the welder, from the effects of optical radiation generated by the welding process. The national and international standards for welding screens and curtains have different requirements. The aim is to compare the protection requirements of examples of welding curtain material and to assess compliance with the international and national standards.

A Need to Revise Human Exposure Limits for Ultraviolet UV-C Radiation.

The COVID-19 pandemic has greatly heightened interest in ultraviolet germicidal irradiation (UVGI) as an important intervention strategy to disinfect air in medical treatment facilities and public indoor spaces. However, a major drawback of UVGI is the challenge posed by assuring safe installation of potentially hazardous short-wavelength (UV-C) ultraviolet lamps. Questions have arisen regarding what appear to be unusually conservative exposure limit values in the UV-C spectral band between 180 and 280 nm.

UV-Photokeratitis Associated with Germicidal Lamps Purchased during the COVID-19 Pandemic.

Purpose: To report photokeratitis caused by the improper use of germicidal lamps purchased during the COVID-19 pandemic.

Methods: Case series.

Results: Seven patients presented with acute ocular surface pain after exposure to UV-emitting germicidal lamps.

Cataract Formation by Near-infrared Radiation in Rabbits.

Surveys and epidemiological studies have shown an increased prevalence of cataracts in workers in the glass and steel industries. These cataracts are associated with exposure to intense infrared radiation (IR) emitted from heated materials and industrial furnaces. Thermal model calculations predicted that near and far IR would cause cataract with different mechanisms.

Technical Report: Solar Ultraviolet Protection from Sunglasses.

Significance: There is substantial scientific uncertainty about the necessary levels of protection in sunglasses to avoid delayed health effects from solar ultraviolet radiation in the ultraviolet A (UV-A) band. The longer-wavelength limit for UV-A and the inclusion of the spectral effectiveness function in the calculation of solar UV-A transmittance are questionable.

Purpose: There has been a wide range of informed opinion with regard to the level-or even need for-near-ultraviolet filtration (by absorption or reflection) in sunglasses.

Pupil Size in Outdoor Environments.

When addressing the risk of laser-induced retinal injury in daylight, an individual's pupil size (diameter) is of great importance since the retinal illumination varies as the square of the pupil size. Pupil size was measured under daylight conditions for 87 subjects to fill the data gap in over a century of laboratory pupillometry studies. Photography with a fixed chin/head rest and digital camera platform was employed to measure pupil diameter of subjects viewing a full-field neutral screen.

Global rise of potential health hazards caused by blue light-induced circadian disruption in modern aging societies.

Mammals receive light information through the eyes, which perform two major functions: image forming vision to see objects and non-image forming adaptation of physiology and behavior to light. Cone and rod photoreceptors form images and send the information via retinal ganglion cells to the brain for image reconstruction. In contrast, nonimage-forming photoresponses vary widely from adjustment of pupil diameter to adaptation of the circadian clock.

Light-emitting-diode induced retinal damage and its wavelength dependency .

Aim: To examine light-emitting-diode (LED)-induced retinal neuronal cell damage and its wavelength-driven pathogenic mechanisms.

Methods: Sprague-Dawley rats were exposed to blue LEDs (460 nm), green LEDs (530 nm), and red LEDs (620 nm). Electroretinography (ERG), Hematoxylin and eosin (H&E) staining, transmission electron microscopy (TEM), terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and immunohistochemical (IHC) staining, Western blotting (WB) and the detection of superoxide anion (O·), hydrogen peroxide (HO), total iron, and ferric (Fe) levels were applied.

Ultraviolet safety assessments of insect light traps.

Near-ultraviolet (UV-A: 315-400 nm), "black-light," electric lamps were invented in 1935 and ultraviolet insect light traps (ILTs) were introduced for use in agriculture around that time. Today ILTs are used indoors in several industries and in food-service as well as in outdoor settings. With recent interest in photobiological lamp safety, safety standards are being developed to test for potentially hazardous ultraviolet emissions.

The dental curing light: A potential health risk.

Powerful blue-light emitting dental curing lights are used in dental offices to photocure resins in the mouth. In addition, many dental personnel use magnification loupes. This study measured the effect of magnification loupes on the "blue light hazard" when the light from a dental curing light was reflected off a human tooth.

Laser-Induced Photic Injury Phenocopies Macular Dystrophy.

Objective: To describe the phenotypes associated with laser-induced retinal damage in children.

Methods: Five patients with maculopathy and reduced visual acuity associated with laser pointer use were evaluated. Best-corrected visual acuity, retinal structure, and function were monitored with color fundus, infrared (IR), and red-free images, fundus autofluorescence (AF), spectral domain-optical coherence tomography (SD-OCT), and full-field electroretinography (ERG).

Interlaboratory Evaluation of Ultraviolet Radiation Emissions from Compact Fluorescent Lamps.

There have been many recent reports regarding the potential risks of UV emissions from compact fluorescent lamps (CFLs). In some of these reports, the robustness of the measurements was difficult to discern. We conducted round-robin measurements, involving three lamp manufacturers and two government research laboratories to gather reliable data on the UV emissions from commercially available CFLs.

Optical safety of comparative theater projectors.

Traditional movie projectors employing carbon arcs were introduced to movie theaters more than a century ago, and they were replaced during the 1950s by xenon-arc projectors. Today, these arc-lamp film projectors are expected to be replaced by digital laser projectors. Questions have arisen with regard to safety of the new laser-based projectors and about the comparable safety to the xenon-arc projectors that they replace.

A new understanding of multiple-pulsed laser-induced retinal injury thresholds.

Laser safety standards committees have struggled for years to formulate adequately a sound method for treating repetitive-pulse laser exposures. Safety standards for lamps and LEDs have ignored this issue because averaged irradiance appeared to treat the issue adequately for large retinal image sizes and skin exposures. Several authors have recently questioned the current approach of three test conditions (i.

White light-emitting diodes (LEDs) at domestic lighting levels and retinal injury in a rat model.

Background: Light-emitting diodes (LEDs) deliver higher levels of blue light to the retina than do conventional domestic light sources. Chronic exposure to high-intensity light (2,000-10,000 lux) has previously been found to result in light-induced retinal injury, but chronic exposure to relatively low-intensity (750 lux) light has not been previously assessed with LEDs in a rodent model.

Objective: We examined LED-induced retinal neuronal cell damage in the Sprague-Dawley rat using functional, histological, and biochemical measurements.

Upper-room ultraviolet germicidal irradiation (UVGI) for air disinfection: a symposium in print.

Upper-room ultraviolet germicidal irradiation (UVGI) has several applications, its most important use is to reduce tuberculosis transmission in high-burden, resource-limited settings, especially those dealing with epidemics of drug-resistant disease. The efficacy of upper-room (UVGI) to reduce the transmission of airborne infection in real-world settings is no longer in question. International application (dosing) guidelines are needed, as are safety standards and commissioning procedures.

Balancing the risk of eye irritation from UV-C with infection from bioaerosols.

The very aspect (phototoxicity) that makes short-wavelength ultraviolet (UV) radiation an effective germicidal agent also is responsible for the unwanted side effects of erythema (reddening of the skin) and photokeratitis ("welder's flash" or "snow-blindness"). Overexposure to this short-wavelength UV radiation can produce these unwanted side effects from a very mild irritation of the skin and eyes to a rather painful case of photokeratitis. These effects are fortunately transient, as only superficial cells of the eye-the corneal epithelium-and the most superficial layer of the skin-the superficial epidermis-are significantly affected.

The susceptibility of the retina to photochemical damage from visible light.

The photoreceptor/RPE complex must maintain a delicate balance between maximizing the absorption of photons for vision and retinal image quality while simultaneously minimizing the risk of photodamage when exposed to bright light. We review the recent discovery of two new effects of light exposure on the photoreceptor/RPE complex in the context of current thinking about the causes of retinal phototoxicity. These effects are autofluorescence photobleaching in which exposure to bright light reduces lipofuscin autofluorescence and, at higher light levels, RPE disruption in which the pattern of autofluorescence is permanently altered following light exposure.