A plasma television has a half-life of about 60,000 hours. This means that it will lose approximately 50% of its brightness during that time. If your Plasma television is switched on eight hours a day, its half-life would be about nine years or if on four hours a day, the half-life would be about eighteen years. Remember that a standard television loses about 30% of its brightness after about 20,000 hours. Because this process is very gradual, the consumer is not aware of this effect, except for the need to periodically adjust the brightness and contrast controls to compensate. Even though the performance of individual Plasma TVs may vary, overall, as a product class, a Plasma television may deliver many years of acceptable viewing.