ultraviolet rays

Ultraviolet rays

Invisible light rays with a wavelength shorter than that of visible light but longer than that of x rays.

Mentioned in: Sunscreens

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ultraviolet (UV) rays

Etymology: L, ultra, beyond; OFr, violette + L, radius

electromagnetic radiations found just beyond the violet edge of the visible spectrum, with wavelengths extending to the beginning of x-rays. The wavelengths range from 390 to 290 nm for near ultraviolet rays to 290 to 20 nm for far ultraviolet wavelengths. Ultraviolet radiation in the region of 260 nm can cause photochemical reactions in deoxyribonucleic molecules, causing mutations and destroying microorganisms, including bacteria and viruses.

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ultraviolet

denoting electromagnetic radiation of wavelength shorter than that of the violet end of the spectrum, having wavelengths of 4-400 nanometers.

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ultraviolet antisepsis

because ultraviolet rays are capable of killing bacteria and other microorganisms, they are sometimes utilized in specially designed cabinets to sterilize objects, and may also be used to sterilize the air in operating rooms and other areas where destruction of bacteria is necessary.

ultraviolet irradiation

the projection of ultraviolet light from a generator is used for the treatment of skin disease and for sterilization of materials.

ultraviolet rays

electromagnetic radiation beyond the violet end of the visible spectrum (at 0.39 to 0.18 μm wavelength) and therefore not visible to humans. They are produced by the sun but are absorbed to a large extent by particles of dust and smoke in the earth's atmosphere. They are also produced by the so-called sun lamps.

Ultraviolet rays can produce sun-burning and affect skin pigmentation. When they strike the skin surface, these rays transform provitamin D, secreted by the glands of the skin, into vitamin D, which is then absorbed into the body.

ultraviolet therapy

the employment of ultraviolet radiation in the treatment of various diseases, particularly those affecting the skin, is used in humans, but not commonly employed in veterinary medicine.

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Patient discussion about ultraviolet rays.

Q. what does a sun block cream do? and what are a UV rays?

A. It blocks out harmful Ultra violet rays from the skin as the previous entries have related; however it can also block your ability to produce vitamin D. If you live in a northerly area or one that receives limited sunlight, its recommended to get at least 15 minutes of sun a day (this is probably best done with minimal sunblock) and according to personnal sun sensitivity. Another thing to keep in mind is that sunblock works best if applied 20 minutes before sun exposure.