Ultraviolet Radiation & Eye Hazards PDF
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This document explores the harmful effects of ultraviolet radiation on the human eye. It describes specific damage mechanisms induced by various wavelengths of UV light, including photochemical damage and thermal effects. The text also details laser-induced eye damage based on wavelength.
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ultraviolet radiation - Students \| Britannica Kids \| Homework Help  PDF\] Adverse effects of ultraviolet radiation from the use of indoor tanning equipment: time to ban the tan. \| Semantic Scholar  PDF\] Adverse effects of ultraviolet radiation from the use of indoor tanning equipment: time to ban the tan. \| Semantic Scholar  Laser effects on the eye The unprotected human eye is extremely sensitive to laser radiation and can be permanently damaged from direct or reflected beams. Due to tissue characteristics, the area of the eye damaged by laser energy is dependent upon the wavelength of the incident laser beam. The retina, cornea, and lens are the areas most commonly damaged. - **Retina:** Laser light in the visible to near-infrared spectrum can cause damage to the retina. These wavelengths are also known as the \"retinal hazard region.\" - Visible and near-infrared (400 -- 1400 nanometer or nm) laser light pose a critical hazard on the retina. Infrared A is transmitted by the cornea to the lens of the eye which narrowly focuses it on the retina, concentrating the radiant exposure of the laser by up to 100,000 times. Since the tissue structures of the retina are unable to undergo any repair, lesions caused by the focusing of visible or near-infrared light on the retina may be permanent. The most critical area of the retina is the central portion, the macula, and the fovea. - **Cornea and lens:** Laser light in the ultraviolet or far-infrared spectrum can cause damage to the cornea or the lens. - Ultraviolet (180 nm to 400 nm): Photochemical damage is caused by the absorption of UV light by selective sensitive portions of cells of the cornea. Many proteins and other molecules (DNA, RNA) absorb UV light and are \"denatured\" by the radiation. Excessive exposure to UV light can cause photophobia, redness of the eye, tearing, discharge, stromal haze, etc. These adverse effects are usually delayed for several hours but will occur within 24 hours. The lens principally absorbs UVA (315-400 nm). The lens is particularly sensitive to the 300 nm wavelength. XeCl eximer lasers operating at 308 nm can cause cataract with an acute exposure. - Far infrared (1400 nm to 1 mm; CO2 lasers, 10600 nm): Thermal damage is caused by the heating of the tears and tissue water of the cornea by the infrared light. Excessive exposure to infrared radiation results in a loss of transparency of the cornea or surface irregularities.
