During the week of April 23, students from local school districts will join millions of children across America participating in National TV-Turnoff Week.

Students, and hopefully their parents, will turn off their televisions and vacate their video game worlds for seven consecutive days. Instead, they will think, read, create, play and simply spend time together.

Millions of families have taken part since this annual event began in 1995. So far as we know, all have survived to tell about it.

"Television is chewing gum for the eyes," celebrated architect Frank Lloyd Wright said. Television can be educational and informative and even enjoyably and harmlessly entertaining, but increasingly, it is instead violent and oversexualized. It glamorizes such vices as tobacco, alcohol and drugs. Evidence of the harmful effects of televised substance abuse, sex and violence on children and adolescents is as compelling as the evidence that smoking causes lung cancer.

Television and other screen media are an enormous and growing presence in children's lives. As parents are increasingly overworked and overstressed, it has come to be less that we are letting our children watch television and more that we are asking television to watch our children.

It is not a matter of being a "good" or "bad" parent. Rather, it is a result of our failure to value and protect parents' right to enjoy quality time with their children.

Consuming media now far surpasses creative, active and social pursuits as the average American child's favorite pastime. Between television, video games and computers, the average child logs 40 hours of screen time every week - more than any activity besides sleep.

On average, children in the U.S. will spend more time in front of the television than in school.

We are raising a generation of digital children, wired but disconnected. As the solitude of screen time replaces the togetherness of family time, detachment replaces attachment. Even if it is spent in the company of other children or family, screen time is little more than shared aloneness.

Trust in others comes from a childhood of shared life experiences. Endless hours of mindless screen time amounts to a childhood filled with empty experiences.

Given that the primary purpose of childhood is to develop competencies for life, children who are raised detached from humanity are less likely as adults to be capable of empathy and consideration, and less willing or able to contribute in meaningful ways to their communities.

Parents are largely clueless about the media-saturated world their children inhabit. Viewing television together as a family is critical, but increasingly uncommon. That's unfortunate, given that a child uses media to learn about culture, but typically lacks the knowledge and experience to recognize what is unrealistic and to discriminate between advertising and programming.

Our children now see the world largely through the eyes of advertisers and media corporations. More than $15 billion is spent annually on marketing to children. Given that the average child sees 20,000 commercials annually, and that children highly influence family purchasing decisions, profit-driven corporations cannot help but exploit this enormous source of revenue.

No force is more central to children's food choices than media. The vast majority of marketing to children involves foods and drinks high in fat, added sugar and salt. Our media say "Lose weight! Look fit!" But at the same time, they shout at our children to "Eat! Drink! Buy!" It is deplorable how food producers seduce children into eating foods that are good for profits but bad for health.

Screen time is directly related to obesity - not surprising, given the average of nine food and drink commercials per half-hour of children's programming. Children who watch four hours of screen media daily have a 30 percent risk for obesity - even higher if the TV is in their bedroom - while the risk falls to 7 percent for children whose daily viewing averages less than one hour.

Television and video games are neither inherently good nor bad. They are resources, and when used wisely for children older than the age of 2 years and limited to less than two hours daily, they can exert a positive or at least harmless influence. But the negative effects of each are real and powerful.

For one week, turn them off and see.

Todd Huffman, M.D., is a pediatrician practicing in Springfield.