Temporary relief of entropion may be provided by the taping of the lower eyelid to the cheek but the treatment is usually surgical. See ectropion; therapeutic soft contact lens; orthopaedic spectacles; tarsus; trichiasis. cicatricial entropion; involutional entropion See entropion.
A Tesla coil is a radio frequency oscillator that drives an air-core double-tuned resonant transformer to produce high voltages at low currents. Tesla's original circuits as well as most modern coils use a simple spark gap to excite oscillations in the tuned transformer.
Tesla developed the coil in 1891, before conventional iron-core transformers were used to power things like lighting systems and telephone circuits. These conventional transformers can't withstand the high frequency and high voltage that the looser coils in Tesla's invention can tolerate.