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Designing for Head and Neck Anatomy
Published in Karen L. LaBat, Karen S. Ryan, Human Body, 2019
Eye protection may be as simple as tinted lenses or as involved as a full face and head mask. Good sunglasses protect the eye from bright sunlight and UVA and UVB rays. UVB is the most damaging to the eye. Industrial processes, such as welding, frequently cause eye injuries (Lombardi et al., 2005). Protective eyewear for welding must provide extensive coverage and fit well to prevent harmful light rays, heat, large and/or small objects, wind, fluids, or chemicals from making contact with the eyes. Contact lens wearers in industrial settings with specific hazardous airborne chemicals need specialized protection, such as indirectly vented goggles, to prevent contamination of the tear layer on the eye (Peate, 2007).
Polarization of Light
Published in Abdul Al-Azzawi, Photonics, 2017
Polarization is another interesting wave property of transverse light waves. Polarization is the principle applied to polarized sunglasses used in protecting the eyes from the sun’s rays under a clear sky. Light waves are propagated in an electromagnetic wave as vibrating electric and magnetic fields, which are perpendicular to the direction of the wave propagation. The human eye cannot distinguish between polarized and unpolarized light. Therefore, an analyser is needed to detect polarized light.
Vision and Illumination
Published in Stephan Konz, Steven Johnson, Work Design, 2018
A fourth approach is to put the filter at the eyes—sunglasses. Sunglasses reduce luminance but not contrast, so they reduce visual acuity. However, in most situations visual acuity is not critical, as capability far exceeds task requirements; thus, people trade off a reduction of surplus capacity for an increase in comfort. Polarized sunglasses, however, filter horizontally polarized light and improve both visual acuity and comfort (Mehan and Bennett, 1973).
Photobiology eye safety for horticultural LED lighting: Transmittance performance of eyewear protection using high-irradiant monochromatic LEDs
Published in Journal of Occupational and Environmental Hygiene, 2018
Sunglasses are the typical personal eyewear protection recommended to shield eyes from bright sunlight, lower wavelength lights, and harmful radiation. Current market available sunglasses are all able to reduce a significant amount of UV wavelength, and transmit sufficient amounts of visible light (particularly green and red wavelengths for traffic signals) as stated in standards.[37,38] However, most sunglasses are sold without any information about their detailed transmittance performances in the visible spectrum.[39,40] This makes the selection of proper eyewear protection difficult for users' specific requirements. Moreover, wearing a set of glasses that inefficiently filters certain spectral regions may cause chronic diseases with damage to the lens and retina.[41] This can be even more harmful to the eyes when wearing glasses with improper transmittance characteristics in certain wavelength regions.[41] Due to the lack of this knowledge, transmittance performances of the available sunglasses or filtering lenses have been characterized based on purposes and lighting applications, including UV protection, dental curing lamps, and surgical LED lamps.[32,39,42–44] For each use, studies were conducted to evaluate eyewear protection and provide detailed information on their transmittance performances, but these studies focused either on specific wavebands or special lamps with specific types of eyewear protection. Knowledge on an eyewear protection's transmittance performance with respect to monochromatic LED lamps and different irradiance levels is still unknown for LED users in the horticultural industry. The performances among different types of eyewear protections available in the market also need to be examined for user's selection.