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New lighting systems have not used magnetic ballasts since the turn of the century, however some older installations still remain. Fluorescent lamps with magnetic ballasts flicker at a normally unnoticeable frequency of 100 or 120 Hz (twice of the utility frequency; the lamp is lit on both the positive and negative half-wave of a cycle).
For example, touching or standing around an antenna while a high-power transmitter is in operation can cause burns. The mechanism is the same as that used in a microwave oven. [6] The heating effect varies with the power and the frequency of the electromagnetic energy, as well as the inverse square of distance to the source. The eyes and testes ...
Patients undergoing photodynamic therapy are at additional risk of adverse photosensitive reactions caused by compact fluorescent light. One cause of cataracts is exposure to ultraviolet light. Provided the level of UV emission from lamps is within safe limits, and the lamp a sufficient distance away from the individual, there should be no ...
Hormones and certain medications can also make pigmented bands in the nails, but be especially watchful for nail cancer symptoms, such as a brown or dark stripe that goes from the cuticle out to ...
Light-emitting diode therapy (LEDT) is a clinical approach that applies different wavelengths of light to cure diseases or conditions with skin-safe lights. Following NASA's innovation in the 1990s with Light Emitting Diodes (LEDs) that emit a specific narrow light spectrum, LED Therapy (LEDT) showed significant potential. [ 1 ]
When radiation deposits enough energy in organic tissue to cause ionization, this tends to break molecular bonds, and thus alter the molecular structure of the irradiated molecules. Less energetic radiation, such as visible light, only causes excitation, not ionization, which is usually dissipated as heat with relatively little chemical damage ...
Furthermore, in addition to these dangers, light therapy may not be an as effective choice in general. Said Palep, "At-home LED devices use lower frequencies, so [they] haven’t proven to be as ...
Light therapy, also called phototherapy or bright light therapy is the exposure to direct sunlight or artificial light at controlled wavelengths in order to treat a variety of medical disorders, including seasonal affective disorder (SAD), circadian rhythm sleep-wake disorders, cancers, neonatal jaundice, and skin wound infections.