Are we breeding a generation of zombie-like couch potatoes who are overweight, have poor social skills, can't concentrate, are ill-mannered, and have few of the values we hold as important in a peaceful, functional society?
This, of course, is an extreme view of what exposure to television and computers is doing to our children.
But there is plenty of research to show that excessive screen time is having adverse effects on our children. The question for parents is: how much TV is too much?
The answer depends on many factors, such as your child's age, the kind of programmes children watch and your value system as a parent.
No matter the content of television, however educational, too much screen time is affecting children, say teachers, and it's cause for concern.
Primary school teachers say they are noticing marked changes in the behaviour of young children, which include lack of concentration, poor language skills and low muscle tone.
Heather Bailey, head of the junior primary department at Herschel Preparatory School, says: "There is no doubt that television has had a most profound effect on children's behaviour. There's an enormous difference in concentration levels; and muscle tone is poor.
"Today's children want instant gratification. I'll tell them I'm going to show a video - they'll want to know if it is animated. The modern child is so technical, but they're also non-physical. They have fine motor co-ordination, but they can't climb trees."
A southern suburbs remedial teacher, who preferred not to be named, said the "TV phenomenon" was of ongoing concern.
"Children are plugged into TV sets for care, entertainment and to get them out of parents' hair. It's a way to placate them and keep them happy.
"We're finding children's bodies aren't developing properly, they're not moving around.
"Language skills picked up from conversations around the table aren't being learned. Speech therapists are having to teach children to support an argument. Children want information in small chunks. Teachers are having to adjust their teaching - change their tone of voice, and give them different activities because their concentration span is short."
Children are watching programmes way beyond their years in terms of understanding. "If you're going to let them watch soaps, and you're not there to guide them, you're setting the child's patterning (with the values on the soaps) for life."
She also says creativity has taken a knock: "We are stunting their imaginations, and this has huge implications for reading. I'm a mother myself and I'm extremely cautious with violence, even on the news, I think it has an impact. It's time parents took a moral stand on television."
Remedial teacher Cherry Howell started teaching before the advent of television in South Africa in 1976. "Now I'm dealing with second-generation TV watchers. And their parents' attitude is: 'I watched TV and I'm okay'."
The point is that television's content has changed hugely since it was first introduced in South Africa in 1975, and with the advent of DStv so has the choice of programming.
"Our statistics show that two out of three children watch three to five hours of TV and on the weekend five to 10 hours. If a family can afford another television, the child has it in their room. What this means is that they eat, sleep and interact in front of a television - they're watching through a window into an unrealistic world."
Research done in the UK shows that the amount of TV watched is related to:
- IQ - more intelligent people watch less television.
- Level of personal security - self-esteem is low in TV junkies.
- Level of social adjustment - social misfits don't have to interact with the world.
"TV is static for the human brain. There's no stimulation. When I show a video to the class, the brighter ones switch off quickly," says Howell.
People often justify TV viewing by saying it's educational. While that may be true for some of its content, the form itself is problematic.
Peter van Alphen is a teacher trainer at the Centre for Creative Education, which trains Waldorf School teachers.
"We get parents to understand the effects of television, and how it stops children being active and creative, their natural child-like way of being.
"TV is a passive experience: children grow and learn by being active. TV affects the senses of the child; it's an artificial medium - their eyes have to work harder, the human voice is not real. While television may have some good content, the fact is the child is still inactive. And it tires the child."
Watching TV has the same effect on the brain as being in a dark cupboard, says Howell - it doesn't react.
"The child's attention span should be one minute per year of age (from the time she pays attention to the time she's distracted).
Children today have shorter attention spans - they watch a constantly moving visual field, so to sit still and look at a teacher, who doesn't change, is difficult."
For Howell, it's a questions of the values you want your child to grow up with.
"The values television espouses are that it's good to have a lot of money; having a good time is everything - pleasure is all. Self and instant gratification are important."
But, says Howell, the bottom line is that we take in 80 percent of our knowledge through our senses, and of that 90 percent of our information is gathered through hearing.
"TV is almost totally visual. Children under the age of five and six cannot listen and look at the same time, so they focus on the visual images on TV."
Television, however, is a fact of life, and there is a way to use it creatively.
Van Alphen says: "We ask parents not to let young children, from birth to about four years old, watch TV. After that age, let them watch in a restricted way. Select programmes carefully. Parents have to be tough, for the sake of their children."
A lot of parents do restrict TV watching, says Bailey.
Teacher Cherry Howell says she can tell when children have been watching too much or inappropriate television.
- The way they speak to adults, peers and parents - as though they're in a sitcom. They speak in Americanese, in monosyllables, and pause for the canned laughter.
- Sentences run on - they can't speak properly. They're good at answering, but don't initiate discussions.
- The way they learn - they're passive learners and don't know how to think logically
- Their attitude to life - sit back and let others entertain them.
- On Monday morning, children are lethargic, systems are recovering, they've been eating junk food and watching TV, going to bed late.
- Children under two should have no "screen time" (TV, DVDs or videotapes, computers, or video games) at all. During the first two years, a critical time for brain development, TV can get in the way of exploring, learning and spending time interacting and playing, which helps young children develop the skills they need to grow cognitively, physically, socially, and emotionally.
- Children over two should watch no more than 1-2 hours a day of quality programming.
- It's important for parents to monitor the content of TV programmes and set viewing limits
- Limit the number of TV-watching hours.
- Stock the room in which you have your TV with plenty of non-screen fun (books, magazines, toys, puzzles, board games) to encourage your child to do something other than watch TV.
- Keep TVs out of your child's bedroom.
- Turn the TV off during meals.
- Don't allow your child to watch TV while doing homework.
- Treat TV as a privilege your child needs to earn - not a right.
- Try a weekday ban. Record weekday shows or save TV time for weekends, and you'll have more family time for meals, games, physical activity, and reading during the week.
- Set a good example by limiting your own viewing.
- Watch TV with your child. If you can't sit through the whole programme, at least watch the first few minutes to assess the tone and appropriateness, then check in throughout the show.
- Talk to your child about what he or she sees on TV and share your own beliefs and values.
- Offer fun alternatives to TV.