Basic knowledge of sunglasses: optical radiation protection
Sunglasses in addition to can reduce the radiation intensity of visible light, can also reduce the ultraviolet and infrared radiation. Polarized sunglasses can also be used to eliminate the water, snow, reflecting the gravel road surface level. Sunglasses cash more endowed with fashionable breath. But the fundamental role of sunglasses is to provide radiation protection for the eyes. On the basic requirement of sunglasses are: eliminate unwanted radiation may have damage to the eyes; Reduce the environment light intensity into eyes, provide clear, comfortable functional vision; Can maintain normal color vision, reflected in the rapid and accurate identification of traffic lights; Maintaining quantity dark adaptation or night vision; Shock resistance and good wear resistance performance. This paper mainly introduces the basic knowledge of sunglasses of optical radiation protection in the principle of optical radiation protection. 1. The principle of optical radiation protection eye tissues caused by the radiation damage may be immediate, also may be cumulative. General principles of radiation protection is 'nip in the bud. Here are used to assess whether the environmental radiation to need several protective level: ( 1) Safety exposure limit ( 安全暴露时间,SED) Is to organize radiation exposure of the ratio between threshold and light irradiation intensity. SED can then be used to calculate the UV protection, VIS and IR. Light source can be l-band, also can be a short wave period, as long as the tissue exposed threshold and light radiation intensity is in the same range of wavelengths. SED can also be used to assess filter provides protection function. ( 2) Protection factor ( 保护因素,PF) Cause damage to the organization of the radiation intensity of the ratio between threshold and light irradiation intensity. Can be used to calculate the UV VIS and IR spectrum of electromagnetic radiation damage. ( 3) Effects of relative coefficient ( 相对有效性,再保险) In 200 nm to 320 nm uv band, can cause damage to the photosensitive keratitis, cataracts and other relative weight coefficient of different wavelengths, is l to 270 nm. 00.